We have reasonably hard water -- municipal well sourced along with
CAP.

I've plumbed the "outdoor water supplies" (i.e., irrigation and hose
bibbs) to use water directly from the municipal supply (i.e., NOT
"locally" treated) as I don't want to be paying to "treat" water
that's going out a garden hose, etc.

[I don't think the plants would like the extra salt, regardless]

There are ~20 solenoid operated valves buried around the yard
(little concrete, covered vaults that I built for them). Each
operates an irrigation "zone" *or* one of the 4 hose bibbs
scattered around the perimeter.

The irrigation *lines* are all below grade. So, essentially safe
from freezes. But, the hose bibbs require the water supply
(exiting the solenoid valve) to climb to a height that is
convenient for a human user to access. So, that portion of
the plumbing that is above grade is exposed to the elements
more than the rest of the lines which remain below grade.

These risers are 3/4" copper run through the "voids" in 8"
"half (cinder) blocks" which have then been filled with
"Nasty Foam" (TmReg) to improve insulation.

So, you have a length of copper pipe that exits the solenoid valve,
rises through the surface of the soil *into* this foam-filled
void and terminates at a hose bibb -- the valve of which might be
open or closed

[no idea as to which; the whole point of the solenoid is to allow
me to put a garden hose on a bibb, set the (manual) valve to an
appropriate flow rate, and direct the hose's output to a
particular spot in the yard that needs "supplemental watering".
Then, use the solenoid to turn that water supply on or off.]

Of course, I don't want to risk the water standing in that pipe
freezing and rupturing the pipe (I can't rely on it destroying
the valve, instead : ).

To that end, I installed these auto-drain valves (colloquially
known as "spitters") on the "load" side of the solenoid.
They resemble a PCV valve in construction: an opening which
can be plugged by a slug of metal inside the valve body.
A low tension spring holds the plug AWAY from the opening
so it is normally open. The slightest water pressure acts
to push the slug (plug) against the hole thereby sealing it.

When pressure is removed, the spring's force eventually
overcomes that of the fading water pressure and the slug
exposes the opening. As this is located at the low point
in the plumbing, the water "standing" above it *should*
drain out through this opening.

[This is a sort of *******ization of their use]

Over time, I suspect these will fail due to concretions
from the water supply. Anyone know for a fact if this is
true? I've located them in a way that allows me to
service them down the road. But, I'm looking for FEWER
chores, not MORE! :

Alternatively, I'm considering forcing all of the solenoids
*open* (after turning off the main supply) and hoping water
will "seek its level" throughout the system -- instead of
dealing with each of these little "stand pipes" in isolation.

[Or, even adding an "extra" valve whose sole purpose is to be
the "low point" in the system so there is a place BELOW GRADE
for all water to drain]

On 11/22/15 4:04 PM, Don Y wrote:
We have reasonably hard water -- municipal well sourced along with
CAP.

I've plumbed the "outdoor water supplies" (i.e., irrigation and hose
bibbs) to use water directly from the municipal supply (i.e., NOT
"locally" treated) as I don't want to be paying to "treat" water
that's going out a garden hose, etc.

[I don't think the plants would like the extra salt, regardless]

There are ~20 solenoid operated valves buried around the yard
(little concrete, covered vaults that I built for them). Each
operates an irrigation "zone" *or* one of the 4 hose bibbs
scattered around the perimeter.

The irrigation *lines* are all below grade. So, essentially safe
from freezes. But, the hose bibbs require the water supply
(exiting the solenoid valve) to climb to a height that is
convenient for a human user to access. So, that portion of
the plumbing that is above grade is exposed to the elements
more than the rest of the lines which remain below grade.

These risers are 3/4" copper run through the "voids" in 8"
"half (cinder) blocks" which have then been filled with
"Nasty Foam" (TmReg) to improve insulation.

So, you have a length of copper pipe that exits the solenoid valve,
rises through the surface of the soil *into* this foam-filled
void and terminates at a hose bibb -- the valve of which might be
open or closed

[no idea as to which; the whole point of the solenoid is to allow
me to put a garden hose on a bibb, set the (manual) valve to an
appropriate flow rate, and direct the hose's output to a
particular spot in the yard that needs "supplemental watering".
Then, use the solenoid to turn that water supply on or off.]

Of course, I don't want to risk the water standing in that pipe
freezing and rupturing the pipe (I can't rely on it destroying
the valve, instead : ).

To that end, I installed these auto-drain valves (colloquially
known as "spitters") on the "load" side of the solenoid.
They resemble a PCV valve in construction: an opening which
can be plugged by a slug of metal inside the valve body.
A low tension spring holds the plug AWAY from the opening
so it is normally open. The slightest water pressure acts
to push the slug (plug) against the hole thereby sealing it.

When pressure is removed, the spring's force eventually
overcomes that of the fading water pressure and the slug
exposes the opening. As this is located at the low point
in the plumbing, the water "standing" above it *should*
drain out through this opening.

[This is a sort of *******ization of their use]

Over time, I suspect these will fail due to concretions
from the water supply. Anyone know for a fact if this is
true? I've located them in a way that allows me to
service them down the road. But, I'm looking for FEWER
chores, not MORE! :

Alternatively, I'm considering forcing all of the solenoids
*open* (after turning off the main supply) and hoping water
will "seek its level" throughout the system -- instead of
dealing with each of these little "stand pipes" in isolation.

[Or, even adding an "extra" valve whose sole purpose is to be
the "low point" in the system so there is a place BELOW GRADE
for all water to drain]

Is blowing the lines out with compressed air not feasible for some
reason ?

(FWIW, I once had one of those "auto" valves stick open. What a mess !)

On Sun, 22 Nov 2015 14:04:23 -0700, Don Y
wrote:

We have reasonably hard water -- municipal well sourced along with
CAP.

I've plumbed the "outdoor water supplies" (i.e., irrigation and hose
bibbs) to use water directly from the municipal supply (i.e., NOT
"locally" treated) as I don't want to be paying to "treat" water
that's going out a garden hose, etc.

[I don't think the plants would like the extra salt, regardless]

There are ~20 solenoid operated valves buried around the yard
(little concrete, covered vaults that I built for them). Each
operates an irrigation "zone" *or* one of the 4 hose bibbs
scattered around the perimeter.

The irrigation *lines* are all below grade. So, essentially safe
from freezes. But, the hose bibbs require the water supply
(exiting the solenoid valve) to climb to a height that is
convenient for a human user to access. So, that portion of
the plumbing that is above grade is exposed to the elements
more than the rest of the lines which remain below grade.

These risers are 3/4" copper run through the "voids" in 8"
"half (cinder) blocks" which have then been filled with
"Nasty Foam" (TmReg) to improve insulation.

So, you have a length of copper pipe that exits the solenoid valve,
rises through the surface of the soil *into* this foam-filled
void and terminates at a hose bibb -- the valve of which might be
open or closed

[no idea as to which; the whole point of the solenoid is to allow
me to put a garden hose on a bibb, set the (manual) valve to an
appropriate flow rate, and direct the hose's output to a
particular spot in the yard that needs "supplemental watering".
Then, use the solenoid to turn that water supply on or off.]

Of course, I don't want to risk the water standing in that pipe
freezing and rupturing the pipe (I can't rely on it destroying
the valve, instead : ).

To that end, I installed these auto-drain valves (colloquially
known as "spitters") on the "load" side of the solenoid.
They resemble a PCV valve in construction: an opening which
can be plugged by a slug of metal inside the valve body.
A low tension spring holds the plug AWAY from the opening
so it is normally open. The slightest water pressure acts
to push the slug (plug) against the hole thereby sealing it.

When pressure is removed, the spring's force eventually
overcomes that of the fading water pressure and the slug
exposes the opening. As this is located at the low point
in the plumbing, the water "standing" above it *should*
drain out through this opening.

[This is a sort of *******ization of their use]

Over time, I suspect these will fail due to concretions
from the water supply. Anyone know for a fact if this is
true? I've located them in a way that allows me to
service them down the road. But, I'm looking for FEWER
chores, not MORE! :

Alternatively, I'm considering forcing all of the solenoids
*open* (after turning off the main supply) and hoping water
will "seek its level" throughout the system -- instead of
dealing with each of these little "stand pipes" in isolation.

[Or, even adding an "extra" valve whose sole purpose is to be
the "low point" in the system so there is a place BELOW GRADE
for all water to drain]

Not sure what your question is. Sounds like you are talking about
positive drain valves; either for irrigation, but also work for solar
pool panels. I have hard water for the pool. Never had a problem on
the pool solar panel or the valve not functioning as intended due to
minerals.

Am I close?

On Sunday, November 22, 2015 at 3:03:59 PM UTC-6, Don Y wrote:
We have reasonably hard water -- municipal well sourced along with
CAP.

I've plumbed the "outdoor water supplies" (i.e., irrigation and hose
bibbs) to use water directly from the municipal supply (i.e., NOT
"locally" treated) as I don't want to be paying to "treat" water
that's going out a garden hose, etc.

[I don't think the plants would like the extra salt, regardless]

There are ~20 solenoid operated valves buried around the yard
(little concrete, covered vaults that I built for them). Each
operates an irrigation "zone" *or* one of the 4 hose bibbs
scattered around the perimeter.

The irrigation *lines* are all below grade. So, essentially safe
from freezes. But, the hose bibbs require the water supply
(exiting the solenoid valve) to climb to a height that is
convenient for a human user to access. So, that portion of
the plumbing that is above grade is exposed to the elements
more than the rest of the lines which remain below grade.

These risers are 3/4" copper run through the "voids" in 8"
"half (cinder) blocks" which have then been filled with
"Nasty Foam" (TmReg) to improve insulation.

So, you have a length of copper pipe that exits the solenoid valve,
rises through the surface of the soil *into* this foam-filled
void and terminates at a hose bibb -- the valve of which might be
open or closed

[no idea as to which; the whole point of the solenoid is to allow
me to put a garden hose on a bibb, set the (manual) valve to an
appropriate flow rate, and direct the hose's output to a
particular spot in the yard that needs "supplemental watering".
Then, use the solenoid to turn that water supply on or off.]

Of course, I don't want to risk the water standing in that pipe
freezing and rupturing the pipe (I can't rely on it destroying
the valve, instead : ).

To that end, I installed these auto-drain valves (colloquially
known as "spitters") on the "load" side of the solenoid.
They resemble a PCV valve in construction: an opening which
can be plugged by a slug of metal inside the valve body.
A low tension spring holds the plug AWAY from the opening
so it is normally open. The slightest water pressure acts
to push the slug (plug) against the hole thereby sealing it.

When pressure is removed, the spring's force eventually
overcomes that of the fading water pressure and the slug
exposes the opening. As this is located at the low point
in the plumbing, the water "standing" above it *should*
drain out through this opening.

[This is a sort of *******ization of their use]

Over time, I suspect these will fail due to concretions
from the water supply. Anyone know for a fact if this is
true? I've located them in a way that allows me to
service them down the road. But, I'm looking for FEWER
chores, not MORE! :

Alternatively, I'm considering forcing all of the solenoids
*open* (after turning off the main supply) and hoping water
will "seek its level" throughout the system -- instead of
dealing with each of these little "stand pipes" in isolation.

[Or, even adding an "extra" valve whose sole purpose is to be
the "low point" in the system so there is a place BELOW GRADE
for all water to drain]

I've used a shop-vac to clear long 3/4 inch drain lines, I wonder if you could clear your irrigation lines that way? Perhaps use the shop-vac to move nontoxic antifreeze through your pipes? ^_^

[8~{} Uncle Vac Monster

On 11/22/2015 2:17 PM, Retired wrote:
On 11/22/15 4:04 PM, Don Y wrote:
We have reasonably hard water -- municipal well sourced along with
CAP.

I've plumbed the "outdoor water supplies" (i.e., irrigation and hose
bibbs) to use water directly from the municipal supply (i.e., NOT
"locally" treated) as I don't want to be paying to "treat" water
that's going out a garden hose, etc.

[I don't think the plants would like the extra salt, regardless]

There are ~20 solenoid operated valves buried around the yard
(little concrete, covered vaults that I built for them). Each
operates an irrigation "zone" *or* one of the 4 hose bibbs
scattered around the perimeter.

The irrigation *lines* are all below grade. So, essentially safe
from freezes. But, the hose bibbs require the water supply
(exiting the solenoid valve) to climb to a height that is
convenient for a human user to access. So, that portion of
the plumbing that is above grade is exposed to the elements
more than the rest of the lines which remain below grade.

These risers are 3/4" copper run through the "voids" in 8"
"half (cinder) blocks" which have then been filled with
"Nasty Foam" (TmReg) to improve insulation.

So, you have a length of copper pipe that exits the solenoid valve,
rises through the surface of the soil *into* this foam-filled
void and terminates at a hose bibb -- the valve of which might be
open or closed

[no idea as to which; the whole point of the solenoid is to allow
me to put a garden hose on a bibb, set the (manual) valve to an
appropriate flow rate, and direct the hose's output to a
particular spot in the yard that needs "supplemental watering".
Then, use the solenoid to turn that water supply on or off.]

Of course, I don't want to risk the water standing in that pipe
freezing and rupturing the pipe (I can't rely on it destroying
the valve, instead : ).

To that end, I installed these auto-drain valves (colloquially
known as "spitters") on the "load" side of the solenoid.
They resemble a PCV valve in construction: an opening which
can be plugged by a slug of metal inside the valve body.
A low tension spring holds the plug AWAY from the opening
so it is normally open. The slightest water pressure acts
to push the slug (plug) against the hole thereby sealing it.

When pressure is removed, the spring's force eventually
overcomes that of the fading water pressure and the slug
exposes the opening. As this is located at the low point
in the plumbing, the water "standing" above it *should*
drain out through this opening.

[This is a sort of *******ization of their use]

Over time, I suspect these will fail due to concretions
from the water supply. Anyone know for a fact if this is
true? I've located them in a way that allows me to
service them down the road. But, I'm looking for FEWER
chores, not MORE! :

Alternatively, I'm considering forcing all of the solenoids
*open* (after turning off the main supply) and hoping water
will "seek its level" throughout the system -- instead of
dealing with each of these little "stand pipes" in isolation.

[Or, even adding an "extra" valve whose sole purpose is to be
the "low point" in the system so there is a place BELOW GRADE
for all water to drain]

Is blowing the lines out with compressed air not feasible for some reason ?

How would I do that? This is intended for "unattended operation".
E.g., today, irrigation zones 3, 7, 8 and 14 might be used -- individually
or in some combination. Tomorrow, hose bibb #2 might see some use
and the *solenoid* for bibb #4 might be engaged -- but, someone may have
turned off the (manual) valve/bibb (because they decided this
supplemental water was no longer needed yet hadn't got 'round to
updating the "programmed watering schedule", yet).

So, if I force air through from the *supply*, there's no guarantee it
will have a means of "exit" (assuming I deliberately open all desired
solenoids).

And, I can't push air through from the "output" end (obvious reasons).

(FWIW, I once had one of those "auto" valves stick open. What a mess !)

That's what worries me. These are hidden and below grade. I have made
drainage provisions for a little "spitting" that is inevitable with each
actuation of the device. But, if it failed open (even partially so),
I'd never know it unless the valve vault overflowed with water
(and, I happened to be outside to notice it!)

Don Y wrote:
On 11/22/2015 2:17 PM, Retired wrote:
On 11/22/15 4:04 PM, Don Y wrote:
We have reasonably hard water -- municipal well sourced along with
CAP.

I've plumbed the "outdoor water supplies" (i.e., irrigation and hose
bibbs) to use water directly from the municipal supply (i.e., NOT
"locally" treated) as I don't want to be paying to "treat" water
that's going out a garden hose, etc.

[I don't think the plants would like the extra salt, regardless]

There are ~20 solenoid operated valves buried around the yard
(little concrete, covered vaults that I built for them). Each
operates an irrigation "zone" *or* one of the 4 hose bibbs
scattered around the perimeter.

The irrigation *lines* are all below grade. So, essentially safe
from freezes. But, the hose bibbs require the water supply
(exiting the solenoid valve) to climb to a height that is
convenient for a human user to access. So, that portion of
the plumbing that is above grade is exposed to the elements
more than the rest of the lines which remain below grade.

These risers are 3/4" copper run through the "voids" in 8"
"half (cinder) blocks" which have then been filled with
"Nasty Foam" (TmReg) to improve insulation.

So, you have a length of copper pipe that exits the solenoid valve,
rises through the surface of the soil *into* this foam-filled
void and terminates at a hose bibb -- the valve of which might be
open or closed

[no idea as to which; the whole point of the solenoid is to allow
me to put a garden hose on a bibb, set the (manual) valve to an
appropriate flow rate, and direct the hose's output to a
particular spot in the yard that needs "supplemental watering".
Then, use the solenoid to turn that water supply on or off.]

Of course, I don't want to risk the water standing in that pipe
freezing and rupturing the pipe (I can't rely on it destroying
the valve, instead : ).

To that end, I installed these auto-drain valves (colloquially
known as "spitters") on the "load" side of the solenoid.
They resemble a PCV valve in construction: an opening which
can be plugged by a slug of metal inside the valve body.
A low tension spring holds the plug AWAY from the opening
so it is normally open. The slightest water pressure acts
to push the slug (plug) against the hole thereby sealing it.

When pressure is removed, the spring's force eventually
overcomes that of the fading water pressure and the slug
exposes the opening. As this is located at the low point
in the plumbing, the water "standing" above it *should*
drain out through this opening.

[This is a sort of *******ization of their use]

Over time, I suspect these will fail due to concretions
from the water supply. Anyone know for a fact if this is
true? I've located them in a way that allows me to
service them down the road. But, I'm looking for FEWER
chores, not MORE! :

Alternatively, I'm considering forcing all of the solenoids
*open* (after turning off the main supply) and hoping water
will "seek its level" throughout the system -- instead of
dealing with each of these little "stand pipes" in isolation.

[Or, even adding an "extra" valve whose sole purpose is to be
the "low point" in the system so there is a place BELOW GRADE
for all water to drain]

Is blowing the lines out with compressed air not feasible for some
reason ?

How would I do that? This is intended for "unattended operation".
E.g., today, irrigation zones 3, 7, 8 and 14 might be used --
individually or in some combination. Tomorrow, hose bibb #2 might
see some use and the *solenoid* for bibb #4 might be engaged -- but, someone
may
have turned off the (manual) valve/bibb (because they decided this
supplemental water was no longer needed yet hadn't got 'round to
updating the "programmed watering schedule", yet).

So, if I force air through from the *supply*, there's no guarantee it
will have a means of "exit" (assuming I deliberately open all desired
solenoids).

You apply the air pressure from the source end, then cycle through the valves,
opening each until you get mostly air from the sprinklers on that valve. I've
heard a fairly large air supply is best for this. I use my 5HP compressor.

On 11/23/2015 10:39 AM, Bob F wrote:
Don Y wrote:
On 11/22/2015 2:17 PM, Retired wrote:
On 11/22/15 4:04 PM, Don Y wrote:
We have reasonably hard water -- municipal well sourced along with
CAP.

I've plumbed the "outdoor water supplies" (i.e., irrigation and hose
bibbs) to use water directly from the municipal supply (i.e., NOT
"locally" treated) as I don't want to be paying to "treat" water
that's going out a garden hose, etc.

[I don't think the plants would like the extra salt, regardless]

There are ~20 solenoid operated valves buried around the yard
(little concrete, covered vaults that I built for them). Each
operates an irrigation "zone" *or* one of the 4 hose bibbs
scattered around the perimeter.

The irrigation *lines* are all below grade. So, essentially safe
from freezes. But, the hose bibbs require the water supply
(exiting the solenoid valve) to climb to a height that is
convenient for a human user to access. So, that portion of
the plumbing that is above grade is exposed to the elements
more than the rest of the lines which remain below grade.

These risers are 3/4" copper run through the "voids" in 8"
"half (cinder) blocks" which have then been filled with
"Nasty Foam" (TmReg) to improve insulation.

So, you have a length of copper pipe that exits the solenoid valve,
rises through the surface of the soil *into* this foam-filled
void and terminates at a hose bibb -- the valve of which might be
open or closed

[no idea as to which; the whole point of the solenoid is to allow
me to put a garden hose on a bibb, set the (manual) valve to an
appropriate flow rate, and direct the hose's output to a
particular spot in the yard that needs "supplemental watering".
Then, use the solenoid to turn that water supply on or off.]

Of course, I don't want to risk the water standing in that pipe
freezing and rupturing the pipe (I can't rely on it destroying
the valve, instead : ).

To that end, I installed these auto-drain valves (colloquially
known as "spitters") on the "load" side of the solenoid.
They resemble a PCV valve in construction: an opening which
can be plugged by a slug of metal inside the valve body.
A low tension spring holds the plug AWAY from the opening
so it is normally open. The slightest water pressure acts
to push the slug (plug) against the hole thereby sealing it.

When pressure is removed, the spring's force eventually
overcomes that of the fading water pressure and the slug
exposes the opening. As this is located at the low point
in the plumbing, the water "standing" above it *should*
drain out through this opening.

[This is a sort of *******ization of their use]

Over time, I suspect these will fail due to concretions
from the water supply. Anyone know for a fact if this is
true? I've located them in a way that allows me to
service them down the road. But, I'm looking for FEWER
chores, not MORE! :

Alternatively, I'm considering forcing all of the solenoids
*open* (after turning off the main supply) and hoping water
will "seek its level" throughout the system -- instead of
dealing with each of these little "stand pipes" in isolation.

[Or, even adding an "extra" valve whose sole purpose is to be
the "low point" in the system so there is a place BELOW GRADE
for all water to drain]

Is blowing the lines out with compressed air not feasible for some
reason ?

How would I do that? This is intended for "unattended operation".
E.g., today, irrigation zones 3, 7, 8 and 14 might be used --
individually or in some combination. Tomorrow, hose bibb #2 might
see some use and the *solenoid* for bibb #4 might be engaged -- but, someone
may
have turned off the (manual) valve/bibb (because they decided this
supplemental water was no longer needed yet hadn't got 'round to
updating the "programmed watering schedule", yet).

So, if I force air through from the *supply*, there's no guarantee it
will have a means of "exit" (assuming I deliberately open all desired
solenoids).

You apply the air pressure from the source end, then cycle through the valves,
opening each until you get mostly air from the sprinklers on that valve. I've
heard a fairly large air supply is best for this. I use my 5HP compressor.

That seems even more problematic! Now I need a way of (electronically)
disconnecting the water supply line from the "outdoor distribution
system" and connecting an air supply in its place. Then, a means of
ensuring the air pressure never exceeds the working limits of the
plastic and copper pipe and other fixtures in the outdoor system.
A way of applying that pressure and knowing when it's done it's trick.

What do I do if the hose bibbs are closed? Where does the water
"standing" in the riser pipe go? If I open the solenoid valve and it
manages to drain down "backwards, through the solenoid valve to
come to rest "below grade", how is the air pressure going to force
it through the CLOSED hose bibb??

I.e., you need a means of creating an "exit point" -- like these
"spitters" -- if you want the water to leave the system.
(If it just "runs backwards" then you're doing nothing special
with the air supply that wouldn't happen in its absence!)

[I'm not sure the "standing" water will flow back down without
a means for air to displace it from above. I'm sure there's
a formula for water surface tension vs. gravity someplace
that would indicate how large a dia would be required for the
water to "fall" from its own weight. Imagine water in a
soda straw with the top end pinched shut. It's not going
to "fall back down" without "encouragement"]

The whole point of all this is to be able to have it all happen
"unattended". E.g., if my gizmo notices that "conditions are
appropriate" to supply water through the hose bibb or irrigation
valve in question, *it* should be able to do so AND RETURN THE
HYDRAULICS TO A SAFE STATE (without fear of freezes, etc.)

But, *it* can't physically turn the "knob"/faucet on the hose
bibb to ensure that MECHANICAL valve is open when it needs
for it to be!

"Um, Don... can you please get up and open the valve on
hose bibb #3 so I can drain the lines FOR you?"

On 11/22/2015 2:21 PM, Oren wrote:
On Sun, 22 Nov 2015 14:04:23 -0700, Don Y
wrote:

We have reasonably hard water -- municipal well sourced along with
CAP.

I've plumbed the "outdoor water supplies" (i.e., irrigation and hose
bibbs) to use water directly from the municipal supply (i.e., NOT
"locally" treated) as I don't want to be paying to "treat" water
that's going out a garden hose, etc.

[I don't think the plants would like the extra salt, regardless]

There are ~20 solenoid operated valves buried around the yard
(little concrete, covered vaults that I built for them). Each
operates an irrigation "zone" *or* one of the 4 hose bibbs
scattered around the perimeter.

The irrigation *lines* are all below grade. So, essentially safe
from freezes. But, the hose bibbs require the water supply
(exiting the solenoid valve) to climb to a height that is
convenient for a human user to access. So, that portion of
the plumbing that is above grade is exposed to the elements
more than the rest of the lines which remain below grade.

These risers are 3/4" copper run through the "voids" in 8"
"half (cinder) blocks" which have then been filled with
"Nasty Foam" (TmReg) to improve insulation.

So, you have a length of copper pipe that exits the solenoid valve,
rises through the surface of the soil *into* this foam-filled
void and terminates at a hose bibb -- the valve of which might be
open or closed

[no idea as to which; the whole point of the solenoid is to allow
me to put a garden hose on a bibb, set the (manual) valve to an
appropriate flow rate, and direct the hose's output to a
particular spot in the yard that needs "supplemental watering".
Then, use the solenoid to turn that water supply on or off.]

Of course, I don't want to risk the water standing in that pipe
freezing and rupturing the pipe (I can't rely on it destroying
the valve, instead : ).

To that end, I installed these auto-drain valves (colloquially
known as "spitters") on the "load" side of the solenoid.
They resemble a PCV valve in construction: an opening which
can be plugged by a slug of metal inside the valve body.
A low tension spring holds the plug AWAY from the opening
so it is normally open. The slightest water pressure acts
to push the slug (plug) against the hole thereby sealing it.

When pressure is removed, the spring's force eventually
overcomes that of the fading water pressure and the slug
exposes the opening. As this is located at the low point
in the plumbing, the water "standing" above it *should*
drain out through this opening.

[This is a sort of *******ization of their use]

Over time, I suspect these will fail due to concretions
from the water supply. Anyone know for a fact if this is
true? I've located them in a way that allows me to
service them down the road. But, I'm looking for FEWER
chores, not MORE! :

Alternatively, I'm considering forcing all of the solenoids
*open* (after turning off the main supply) and hoping water
will "seek its level" throughout the system -- instead of
dealing with each of these little "stand pipes" in isolation.

[Or, even adding an "extra" valve whose sole purpose is to be
the "low point" in the system so there is a place BELOW GRADE
for all water to drain]

Not sure what your question is. Sounds like you are talking about
positive drain valves; either for irrigation, but also work for solar
pool panels. I have hard water for the pool. Never had a problem on
the pool solar panel or the valve not functioning as intended due to
minerals.

Am I close?

frown Dunno -- I don't have a pool or solar so I can't imagine
what you're describing. There may be something that serves a
*similar* role in each of those cases... but I'm sure it wouldn't
be exactly this! (Why would you ever routinely drain either
of those "systems"?)

These are (in my case) 3/4" diameter, male threaded on the "business
end". Once installed, they are only ~1/2" thick. The side that remains
exposed consists of a single ~1/4" dia hole in the brass fitting.
Within this hole, a floating "slug" can be seen. At rest, air (and
water) would flow freely through the opening in either direction.

But, pressure from the "inside" of the irrigation line would cause that
floating slug to overcome the slight spring tension that is keeping it
AWAY from the "hole" and, instead, it will seal the hole completely.

http://www.sprinklerwarehouse.com/DV-050-C-p/dv-050-c.htm

(Look at rightmost photo)

In operation, water pressure pushes that slug outward to seal the hole
so water does not escape the pipe (save for a little "spit" out as the
slug moves to close the hole). Once water pressure is removed AND
FALLS BELOW a couple of psi, the spring can once again overcome that
pressure and push the slug away from the hole, thereby creating an
opening, again, through which air can enter or water exit.

We originally used these with our "mister" system to drain the water
from it to protect against freezing (the "spitter" was located below
grade while the "misters" are up above your head -- lots of water
"standing" in that EXPOSED pipe).

But, the misters saw very little use (wasteful of water) so we have no
long-term experience with how they'll hold up to the crud in our water
supply.

And, as I said elsewhere, there's no easy way to see if one of these has
failed as the valve vaults (in which they are located) are below grade.
You'd have to manually open each vault and check for signs of
EXCESSIVE moisture (you expect to see *some* as these things will always
"spit" a little after each cycle).

On 11/23/2015 9:28 PM, Don Y wrote:

http://www.sprinklerwarehouse.com/DV-050-C-p/dv-050-c.htm

(Look at rightmost photo)

In operation, water pressure pushes that slug outward to seal the hole
so water does not escape the pipe (save for a little "spit" out as the
slug moves to close the hole). Once water pressure is removed AND
FALLS BELOW a couple of psi, the spring can once again overcome that
pressure and push the slug away from the hole, thereby creating an
opening, again, through which air can enter or water exit.

In theory, these devices don't do anything in normal operation
(of the solenoid valves). The "irrigation controller" turns on
each solenoid based on a set of criteria (previous/current/predicted
weather conditions, the water needs of the plants that each "zone"
services, etc.). *As* the solenoid comes on, water flows through
the pipe building pressure as it does so. This quickly ends up
causing the "spitter" to close so no water leaves the pipe via
this "exit".

When the irrigation controller decides to turn the solenoid valve
off, water pressure downstream of the solenoid SHOULD fall
(water keeps oozing out "wherever" so the pressure falls as it
does so).

When the pressure falls enough, the spitter opens and provides
an exit for any remaining water "standing" in the pipe.

The controller eventually turns off the MASTER solenoid that
gates water to the entire irrigation (and hose bibb) system.
At that point, it deliberately opens OTHER valves to provide
a means for pressure remaining in the lines to be released.

In the event that the hose bibb downstream from a solenoid valve
is CLOSED, when the solenoid initially is opened (to supply water
to that zone/circuit), there will be no place for the water to
go! As such, the portion of pipe AFTER the solenoid will be
pressurized to the supply pressure through the solenoid valve.
This pressure will force the slug to plug the hole -- and,
remain in that plugged state as long as pressure persists.

With an IDEAL solenoid valve, closing the valve will trap this
pressure on the downstream side of the solenoid valve. The
slug will never move because it's always being forced closed.
Water will "stand" in the pipe *after* the solenoid.

By deliberately turning off the master supply valve and opening the
other (irrigation) valves, the pressure on the upstream side of
this particular solenoid valve will fall. So, if the controller
opens this solenoid valve at that time, the "standing" water
will have a means of finding pressure relief back into the supply
line.

This should open the "slug" and accelerate the draining of that
"standing" portion of the line.

After a short while, the irrigation controller can let all of the
valves return to their closed states -- confident that any water
remaining in the system has fallen to the lowest point *in* that
system.

I.e., I use the solenoid valves for the "other" zones as vents.

Don Y wrote:
On 11/23/2015 10:39 AM, Bob F wrote:
Don Y wrote:
On 11/22/2015 2:17 PM, Retired wrote:
On 11/22/15 4:04 PM, Don Y wrote:
We have reasonably hard water -- municipal well sourced along with
CAP.

I've plumbed the "outdoor water supplies" (i.e., irrigation and
hose bibbs) to use water directly from the municipal supply
(i.e., NOT "locally" treated) as I don't want to be paying to
"treat" water that's going out a garden hose, etc.

[I don't think the plants would like the extra salt, regardless]

There are ~20 solenoid operated valves buried around the yard
(little concrete, covered vaults that I built for them). Each
operates an irrigation "zone" *or* one of the 4 hose bibbs
scattered around the perimeter.

The irrigation *lines* are all below grade. So, essentially safe
from freezes. But, the hose bibbs require the water supply
(exiting the solenoid valve) to climb to a height that is
convenient for a human user to access. So, that portion of
the plumbing that is above grade is exposed to the elements
more than the rest of the lines which remain below grade.

These risers are 3/4" copper run through the "voids" in 8"
"half (cinder) blocks" which have then been filled with
"Nasty Foam" (TmReg) to improve insulation.

So, you have a length of copper pipe that exits the solenoid
valve, rises through the surface of the soil *into* this
foam-filled void and terminates at a hose bibb -- the valve of which might
be
open or closed

[no idea as to which; the whole point of the solenoid is to allow
me to put a garden hose on a bibb, set the (manual) valve to an
appropriate flow rate, and direct the hose's output to a
particular spot in the yard that needs "supplemental watering".
Then, use the solenoid to turn that water supply on or off.]

Of course, I don't want to risk the water standing in that pipe
freezing and rupturing the pipe (I can't rely on it destroying
the valve, instead : ).

To that end, I installed these auto-drain valves (colloquially
known as "spitters") on the "load" side of the solenoid.
They resemble a PCV valve in construction: an opening which
can be plugged by a slug of metal inside the valve body.
A low tension spring holds the plug AWAY from the opening
so it is normally open. The slightest water pressure acts
to push the slug (plug) against the hole thereby sealing it.

When pressure is removed, the spring's force eventually
overcomes that of the fading water pressure and the slug
exposes the opening. As this is located at the low point
in the plumbing, the water "standing" above it *should*
drain out through this opening.

[This is a sort of *******ization of their use]

Over time, I suspect these will fail due to concretions
from the water supply. Anyone know for a fact if this is
true? I've located them in a way that allows me to
service them down the road. But, I'm looking for FEWER
chores, not MORE! :

Alternatively, I'm considering forcing all of the solenoids
*open* (after turning off the main supply) and hoping water
will "seek its level" throughout the system -- instead of
dealing with each of these little "stand pipes" in isolation.

[Or, even adding an "extra" valve whose sole purpose is to be
the "low point" in the system so there is a place BELOW GRADE
for all water to drain]

Is blowing the lines out with compressed air not feasible for some
reason ?

How would I do that? This is intended for "unattended operation".
E.g., today, irrigation zones 3, 7, 8 and 14 might be used --
individually or in some combination. Tomorrow, hose bibb #2 might
see some use and the *solenoid* for bibb #4 might be engaged --
but, someone may
have turned off the (manual) valve/bibb (because they decided this
supplemental water was no longer needed yet hadn't got 'round to
updating the "programmed watering schedule", yet).

So, if I force air through from the *supply*, there's no guarantee
it will have a means of "exit" (assuming I deliberately open all
desired solenoids).

You apply the air pressure from the source end, then cycle through
the valves, opening each until you get mostly air from the
sprinklers on that valve. I've heard a fairly large air supply is
best for this. I use my 5HP compressor.

That seems even more problematic! Now I need a way of
(electronically) disconnecting the water supply line from the
"outdoor distribution system" and connecting an air supply in its
place. Then, a means of ensuring the air pressure never exceeds the
working limits of the plastic and copper pipe and other fixtures in
the outdoor system. A way of applying that pressure and knowing when it's done
it's trick.

What do I do if the hose bibbs are closed? Where does the water
"standing" in the riser pipe go? If I open the solenoid valve and it
manages to drain down "backwards, through the solenoid valve to
come to rest "below grade", how is the air pressure going to force
it through the CLOSED hose bibb??

I.e., you need a means of creating an "exit point" -- like these
"spitters" -- if you want the water to leave the system.
(If it just "runs backwards" then you're doing nothing special
with the air supply that wouldn't happen in its absence!)

[I'm not sure the "standing" water will flow back down without
a means for air to displace it from above. I'm sure there's
a formula for water surface tension vs. gravity someplace
that would indicate how large a dia would be required for the
water to "fall" from its own weight. Imagine water in a
soda straw with the top end pinched shut. It's not going
to "fall back down" without "encouragement"]

The whole point of all this is to be able to have it all happen
"unattended". E.g., if my gizmo notices that "conditions are
appropriate" to supply water through the hose bibb or irrigation
valve in question, *it* should be able to do so AND RETURN THE
HYDRAULICS TO A SAFE STATE (without fear of freezes, etc.)

But, *it* can't physically turn the "knob"/faucet on the hose
bibb to ensure that MECHANICAL valve is open when it needs
for it to be!

"Um, Don... can you please get up and open the valve on
hose bibb #3 so I can drain the lines FOR you?"

You like it complicated. I just drain everything when I shut it down for winter.
It's not likely to freeze any other time.

Your auto drain valves won't do what you want unless there are leaks somewhere.
As long as there is pressure, they won't open. A sprinkler head relieves the
pressure, but a closed faucet won't. You have to shut off the water, and open
the faucets for it to work right. The drains may not work right without air
being able to get in somewhere while the water drains out too.

Good luck.

Don Y wrote:
On 11/23/2015 9:28 PM, Don Y wrote:

http://www.sprinklerwarehouse.com/DV-050-C-p/dv-050-c.htm

(Look at rightmost photo)

In operation, water pressure pushes that slug outward to seal the
hole so water does not escape the pipe (save for a little "spit" out
as the slug moves to close the hole). Once water pressure is
removed AND FALLS BELOW a couple of psi, the spring can once again
overcome that pressure and push the slug away from the hole, thereby
creating an opening, again, through which air can enter or water
exit.

In theory, these devices don't do anything in normal operation
(of the solenoid valves). The "irrigation controller" turns on
each solenoid based on a set of criteria (previous/current/predicted
weather conditions, the water needs of the plants that each "zone"
services, etc.). *As* the solenoid comes on, water flows through
the pipe building pressure as it does so. This quickly ends up
causing the "spitter" to close so no water leaves the pipe via
this "exit".

When the irrigation controller decides to turn the solenoid valve
off, water pressure downstream of the solenoid SHOULD fall
(water keeps oozing out "wherever" so the pressure falls as it
does so).

When the pressure falls enough, the spitter opens and provides
an exit for any remaining water "standing" in the pipe.

The controller eventually turns off the MASTER solenoid that
gates water to the entire irrigation (and hose bibb) system.
At that point, it deliberately opens OTHER valves to provide
a means for pressure remaining in the lines to be released.

In the event that the hose bibb downstream from a solenoid valve
is CLOSED, when the solenoid initially is opened (to supply water
to that zone/circuit), there will be no place for the water to
go! As such, the portion of pipe AFTER the solenoid will be
pressurized to the supply pressure through the solenoid valve.
This pressure will force the slug to plug the hole -- and,
remain in that plugged state as long as pressure persists.

With an IDEAL solenoid valve, closing the valve will trap this
pressure on the downstream side of the solenoid valve. The
slug will never move because it's always being forced closed.
Water will "stand" in the pipe *after* the solenoid.

By deliberately turning off the master supply valve and opening the
other (irrigation) valves, the pressure on the upstream side of
this particular solenoid valve will fall. So, if the controller
opens this solenoid valve at that time, the "standing" water
will have a means of finding pressure relief back into the supply
line.

I don't think the electric valves I have will open unless the supply pressure is
higher than the pressure on the other side of the valve.


This should open the "slug" and accelerate the draining of that
"standing" portion of the line.

Or, the open faucet relieves the pressure so the valves opens. If the faucet is
closed, that may not happen, depending on the design of your control valves.


After a short while, the irrigation controller can let all of the
valves return to their closed states -- confident that any water
remaining in the system has fallen to the lowest point *in* that
system.

I.e., I use the solenoid valves for the "other" zones as vents.

Which may not work.

On 11/23/2015 10:24 PM, Bob F wrote:
You like it complicated. I just drain everything when I shut it down for winter.
It's not likely to freeze any other time.

We don't stop irrigating in the winter. Nor do we stop using the hose
bibbs. The zones that service the citrus trees serve to coat them
with a fine mist on freezing nights -- so, the system isn't ever
"drained".

Your auto drain valves won't do what you want unless there are leaks somewhere.
As long as there is pressure, they won't open. A sprinkler head relieves the
pressure, but a closed faucet won't. You have to shut off the water, and open
the faucets for it to work right. The drains may not work right without air
being able to get in somewhere while the water drains out too.

See other post to Oren. AFTER I am done with "all zones", I turn off the
master solenoid. So, my system is isolated from the municipal water
supply and *that* source of pressure.

Then, I open the IRRIGATION valves -- which feed "sprinklers" (actually,
"drip emitters") so there is a guaranteed means for water (and pressure)
to be purged from the *rest* of the system.

[I.e., "sprinkler" have no manual shut off valves downstream from the
solenoid valve that controls that zone. So, any time that zone's
valve is open, water/pressure leaks out through the emitters that
are served by that zone]

This leaves the circuits fed by the hose bibbs as the only ones that
can be manually "blocked" (shut off downstream). Any hose bibb that
is currently "open" will drain when its solenoid is actuated -- just
like the sprinkler zones.

So, the problem lies with anyhose bibbs that have been manually closed.

If the bibb was closed when there was no standing water in that riser
pipe, then there's nothing to worry about -- there won't be any *more*
when pressure in the supply has been removed.

If the bibb was closed when there was water standing in that riser
(e.g., if the water was flowing at the time someone manually turned
it off) then I need to coax that water out.

I can't open the manual valve on the hose bibb (it's not motorized).

But, *despite* the fact that there is no means for air to enter
the pipe FROM ABOVE (to displace the water that is being drained
out the bottom), opening the solenoid will provide a means for
pressure to be released in that "standing" riser section. Once
pressure releases, the spitter opens.

Water has weight. Even if you don't provide a means for air to
come in FROM ABOVE, the water won't "defy gravity" and just remain
in that pipe. To prove this to yourself, get a bucket of water.
Put something over the top of it to ensure no air remains in the
cavity. Invert the bucket. Remove the cover -- which is now acting
as the "bottom" of that cavity.

Will the water just stay suspended in that inverted bucket?? :

As the diameter of the bucket (container, pipe) shrinks, surface
tension and adhesion will overcome the tendency of gravity to
pull the water out of the bucket (container, pipe). E.g., a
soda straw will hold water "suspended" almost indefinitely
(barring any leaks, evaporation, etc.). A *bucket* will hold
it suspended "never"!

You can prove this to yourself by getting a 3/4" dia pipe
(or a pill bottle or any similar diameter vessel), filling it
and inverting it. It will promptly drain -- air will displace
the water FROM BELOW (if you have removed the water pressure
that would otherwise hold the trapped water *up* -- which is
what my games with the OTHER solenoid valves does!)

On 11/23/2015 10:33 PM, Bob F wrote:
Don Y wrote:
On 11/23/2015 9:28 PM, Don Y wrote:

http://www.sprinklerwarehouse.com/DV-050-C-p/dv-050-c.htm

(Look at rightmost photo)

In operation, water pressure pushes that slug outward to seal the
hole so water does not escape the pipe (save for a little "spit" out
as the slug moves to close the hole). Once water pressure is
removed AND FALLS BELOW a couple of psi, the spring can once again
overcome that pressure and push the slug away from the hole, thereby
creating an opening, again, through which air can enter or water
exit.

In theory, these devices don't do anything in normal operation
(of the solenoid valves). The "irrigation controller" turns on
each solenoid based on a set of criteria (previous/current/predicted
weather conditions, the water needs of the plants that each "zone"
services, etc.). *As* the solenoid comes on, water flows through
the pipe building pressure as it does so. This quickly ends up
causing the "spitter" to close so no water leaves the pipe via
this "exit".

When the irrigation controller decides to turn the solenoid valve
off, water pressure downstream of the solenoid SHOULD fall
(water keeps oozing out "wherever" so the pressure falls as it
does so).

When the pressure falls enough, the spitter opens and provides
an exit for any remaining water "standing" in the pipe.

The controller eventually turns off the MASTER solenoid that
gates water to the entire irrigation (and hose bibb) system.
At that point, it deliberately opens OTHER valves to provide
a means for pressure remaining in the lines to be released.

In the event that the hose bibb downstream from a solenoid valve
is CLOSED, when the solenoid initially is opened (to supply water
to that zone/circuit), there will be no place for the water to
go! As such, the portion of pipe AFTER the solenoid will be
pressurized to the supply pressure through the solenoid valve.
This pressure will force the slug to plug the hole -- and,
remain in that plugged state as long as pressure persists.

With an IDEAL solenoid valve, closing the valve will trap this
pressure on the downstream side of the solenoid valve. The
slug will never move because it's always being forced closed.
Water will "stand" in the pipe *after* the solenoid.

By deliberately turning off the master supply valve and opening the
other (irrigation) valves, the pressure on the upstream side of
this particular solenoid valve will fall. So, if the controller
opens this solenoid valve at that time, the "standing" water
will have a means of finding pressure relief back into the supply
line.

I don't think the electric valves I have will open unless the supply pressure is
higher than the pressure on the other side of the valve.

Which it will be when the supply is pressurized. Unless that downstream
water has frozen in place, the pressure downstream can't exceed the supply
pressure.

[If this becomes a problem, I can simply replace these four valves with
MOTORIZED valves and that issue goes away.]

This should open the "slug" and accelerate the draining of that
"standing" portion of the line.

Or, the open faucet relieves the pressure so the valves opens. If the faucet is
closed, that may not happen, depending on the design of your control valves.

After a short while, the irrigation controller can let all of the
valves return to their closed states -- confident that any water
remaining in the system has fallen to the lowest point *in* that
system.

I.e., I use the solenoid valves for the "other" zones as vents.

Which may not work.

The other valves *will* reliably vent pressure in the supply line.
All of the emitters fed by those valves are below (in elevation)
the hose bibbs. Some are several *feet* below the supply grade
(front yard emmitters are "downhill" from the rest of the yard)

The only likely problem is if the spitters become calcified from
mineral deposits and either stick closed or fail open.

On Mon, 23 Nov 2015 21:28:18 -0700, Don Y
wrote:

http://www.sprinklerwarehouse.com/DV-050-C-p/dv-050-c.htm

(Look at rightmost photo)

In operation, water pressure pushes that slug outward to seal the hole
so water does not escape the pipe (save for a little "spit" out as the
slug moves to close the hole). Once water pressure is removed AND
FALLS BELOW a couple of psi, the spring can once again overcome that
pressure and push the slug away from the hole, thereby creating an
opening, again, through which air can enter or water exit.

We originally used these with our "mister" system to drain the water
from it to protect against freezing (the "spitter" was located below
grade while the "misters" are up above your head -- lots of water
"standing" in that EXPOSED pipe).

But, the misters saw very little use (wasteful of water) so we have no
long-term experience with how they'll hold up to the crud in our water
supply.

And, as I said elsewhere, there's no easy way to see if one of these has
failed as the valve vaults (in which they are located) are below grade.
You'd have to manually open each vault and check for signs of
EXCESSIVE moisture (you expect to see *some* as these things will always
"spit" a little after each cycle).

Those are similar to what I was getting at, but calling them "positive
drain valves". If I can find a URL or PDF I saved years ago I 'll post
it.

Here is an example of another unit.

"Plastic Automatic Drain Valves prevent damage to irrigation system
due to freezing by automatically draining the sprinkler lines when the
water is turned off. Automatic Drain Valves are installed at the
lowest point of each sprinkler zone.

Features and Benefits

Easy to install
3/4" Male Threaded
Opening pressu 3 to 5 psi (0,2 to 0,34 bars)
Closing pressu 5 psi (0,34 bars) or greater
For outdoor use with cold water only"

They go on at ends of each zone. Not in the valve box.

Pics:
https://www.orbitonline.com/products/sprinkler-systems/valves/plastic-valves/automatic-drain/34-plastic-auto-drain-new

Some other information:

http://www.landscapeandirrigation.com/Irrigation/freezedrain.html

I'll look for the URL / PDF.

On 11/24/2015 11:03 AM, Oren wrote:
On Mon, 23 Nov 2015 21:28:18 -0700, Don Y
wrote:

http://www.sprinklerwarehouse.com/DV-050-C-p/dv-050-c.htm

(Look at rightmost photo)

In operation, water pressure pushes that slug outward to seal the hole
so water does not escape the pipe (save for a little "spit" out as the
slug moves to close the hole). Once water pressure is removed AND
FALLS BELOW a couple of psi, the spring can once again overcome that
pressure and push the slug away from the hole, thereby creating an
opening, again, through which air can enter or water exit.

We originally used these with our "mister" system to drain the water
from it to protect against freezing (the "spitter" was located below
grade while the "misters" are up above your head -- lots of water
"standing" in that EXPOSED pipe).

But, the misters saw very little use (wasteful of water) so we have no
long-term experience with how they'll hold up to the crud in our water
supply.

And, as I said elsewhere, there's no easy way to see if one of these has
failed as the valve vaults (in which they are located) are below grade.
You'd have to manually open each vault and check for signs of
EXCESSIVE moisture (you expect to see *some* as these things will always
"spit" a little after each cycle).

Those are similar to what I was getting at, but calling them "positive
drain valves". If I can find a URL or PDF I saved years ago I 'll post
it.

Here is an example of another unit.

"Plastic Automatic Drain Valves prevent damage to irrigation system
due to freezing by automatically draining the sprinkler lines when the
water is turned off. Automatic Drain Valves are installed at the
lowest point of each sprinkler zone.

Features and Benefits

Easy to install
3/4" Male Threaded
Opening pressu 3 to 5 psi (0,2 to 0,34 bars)
Closing pressu 5 psi (0,34 bars) or greater
For outdoor use with cold water only"

They go on at ends of each zone. Not in the valve box.

There's only one "end" of the zone: the *valve* (the
other "end" is the hose bibb located 3 feet directly above it!)
As the valve *is* the lowest point in the line, it's the
logical place for it. I made provisions for the *small*
amounts of water that should come from it (as it transitions
from open-closed) by putting a hole through the cement
floor of the valve vault for this water to drain.

Pics:
https://www.orbitonline.com/products/sprinkler-systems/valves/plastic-valves/automatic-drain/34-plastic-auto-drain-new

Yes, I found that one while searching for the URL I posted.
But, that one is plastic (my parts are brass screwed into copper pipe)

Some other information:

http://www.landscapeandirrigation.com/Irrigation/freezedrain.html

I'll look for the URL / PDF.

How/why do you use these on a swimming pool or solar (water heater?)?

On Tue, 24 Nov 2015 12:21:12 -0700, Don Y
wrote:

How/why do you use these on a swimming pool or solar (water heater?)?

There is an auto / positive drain (2 Inch dia.) at the peak of the
solar panel. It ensures the panel drains completely during winter. It
does freeze hard some years here in the desert. The panel water drains
back into the pool. Not for pool draining.

On 11/24/2015 12:31 PM, Oren wrote:
On Tue, 24 Nov 2015 12:21:12 -0700, Don Y
wrote:

How/why do you use these on a swimming pool or solar (water heater?)?

There is an auto / positive drain (2 Inch dia.) at the peak of the
solar panel. It ensures the panel drains completely during winter.

So, it acts as an air *inlet*, not a water *outlet*?

It
does freeze hard some years here in the desert. The panel water drains
back into the pool. Not for pool draining.

Solar POOL heater?

On Thu, 26 Nov 2015 18:46:42 -0700, Don Y
wrote:

On 11/24/2015 12:31 PM, Oren wrote:
On Tue, 24 Nov 2015 12:21:12 -0700, Don Y
wrote:

How/why do you use these on a swimming pool or solar (water heater?)?

There is an auto / positive drain (2 Inch dia.) at the peak of the
solar panel. It ensures the panel drains completely during winter.

So, it acts as an air *inlet*, not a water *outlet*?


Yes.

It
does freeze hard some years here in the desert. The panel water drains
back into the pool. Not for pool draining.

Solar POOL heater?

Ummm. I mean panels. I have http://www.heliocol.com/ brand.

On 11/27/2015 9:28 AM, Oren wrote:
On Thu, 26 Nov 2015 18:46:42 -0700, Don Y
wrote:

On 11/24/2015 12:31 PM, Oren wrote:
On Tue, 24 Nov 2015 12:21:12 -0700, Don Y
wrote:

How/why do you use these on a swimming pool or solar (water heater?)?

There is an auto / positive drain (2 Inch dia.) at the peak of the
solar panel. It ensures the panel drains completely during winter.

So, it acts as an air *inlet*, not a water *outlet*?

Yes.

OK. In my case, the valve acts as a drain through which the water exits
the vessel (pipe)

It
does freeze hard some years here in the desert. The panel water drains
back into the pool. Not for pool draining.

Solar POOL heater?

Ummm. I mean panels.

As in "Not for panel draining", yes, I understood. But, the fluid
circulating through the panels is "pool water" so the *panel* can drain
back into the *pool*.

(In my case, the *pipe* is draining into the valve vault/soil)

I have http://www.heliocol.com/ brand.

Many folks, here, just put a gazillion feet of coiled black plastic/nylon
pipe on the roof and run the water through that.

OTOH, covering the water surface (esp at night to *retain* any heat)
and letting it soak up the Sun's rays will easily raise the water
temperature a fair bit above ambient (considering it is over 100F
more than 60 days each year, that's considerable).

On Fri, 27 Nov 2015 15:05:51 -0700, Don Y
wrote:

On 11/27/2015 9:28 AM, Oren wrote:
On Thu, 26 Nov 2015 18:46:42 -0700, Don Y
wrote:

On 11/24/2015 12:31 PM, Oren wrote:
On Tue, 24 Nov 2015 12:21:12 -0700, Don Y
wrote:

How/why do you use these on a swimming pool or solar (water heater?)?

There is an auto / positive drain (2 Inch dia.) at the peak of the
solar panel. It ensures the panel drains completely during winter.

So, it acts as an air *inlet*, not a water *outlet*?

Yes.

OK. In my case, the valve acts as a drain through which the water exits
the vessel (pipe)

It
does freeze hard some years here in the desert. The panel water drains
back into the pool. Not for pool draining.

Solar POOL heater?

Ummm. I mean panels.

As in "Not for panel draining", yes, I understood. But, the fluid
circulating through the panels is "pool water" so the *panel* can drain
back into the *pool*.

(In my case, the *pipe* is draining into the valve vault/soil)

I have http://www.heliocol.com/ brand.

Many folks, here, just put a gazillion feet of coiled black plastic/nylon
pipe on the roof and run the water through that.

OTOH, covering the water surface (esp at night to *retain* any heat)
and letting it soak up the Sun's rays will easily raise the water
temperature a fair bit above ambient (considering it is over 100F
more than 60 days each year, that's considerable).

I guess my point was that the irrigation line "auto" drain valve and
the solar panel "drain" valve work basically the same. Water pressure
closes them - no pressure allows them to drain, either into the soil
or into the pool. What I call, maybe not correctly a "positive" drain
valve.

On 11/27/2015 3:54 PM, Oren wrote:

I guess my point was that the irrigation line "auto" drain valve and
the solar panel "drain" valve work basically the same. Water pressure
closes them - no pressure allows them to drain, either into the soil
or into the pool. What I call, maybe not correctly a "positive" drain
valve.

Yes. But I would imagine you'd have less "problems" (hard water
encrustations) with your "set up" than the configuration that
I'm employing.

On Fri, 27 Nov 2015 16:25:17 -0700, Don Y
wrote:

On 11/27/2015 3:54 PM, Oren wrote:

I guess my point was that the irrigation line "auto" drain valve and
the solar panel "drain" valve work basically the same. Water pressure
closes them - no pressure allows them to drain, either into the soil
or into the pool. What I call, maybe not correctly a "positive" drain
valve.

Yes. But I would imagine you'd have less "problems" (hard water
encrustations) with your "set up" than the configuration that
I'm employing.

We have the hardest water in the nation. See the "Lake Mead Bath Tub
Ring". I've not had a problem in over a decade on the solar panel
drain valve. Maybe you worry to much; regarding the irrigation "auto"
drain valves under ground. Picky picky picky.
--
Definition of a camel: A horse designed by a committee

On 11/27/2015 6:16 PM, Oren wrote:
On Fri, 27 Nov 2015 16:25:17 -0700, Don Y
wrote:

On 11/27/2015 3:54 PM, Oren wrote:

I guess my point was that the irrigation line "auto" drain valve and
the solar panel "drain" valve work basically the same. Water pressure
closes them - no pressure allows them to drain, either into the soil
or into the pool. What I call, maybe not correctly a "positive" drain
valve.

Yes. But I would imagine you'd have less "problems" (hard water
encrustations) with your "set up" than the configuration that
I'm employing.

We have the hardest water in the nation. See the "Lake Mead Bath Tub
Ring".

Dunno. Half of our water is well sourced. The other half comes down a
few hundred miles of concrete aqueducts, pipes, etc.

I've not had a problem in over a decade on the solar panel
drain valve. Maybe you worry to much; regarding the irrigation "auto"
drain valves under ground. Picky picky picky.

I'm not keen on creating "maintenance tasks". E.g., I felled ALL
of the trees on the property before I got old enough to make that
a "challenge". I pulled out the lawn so it wouldn't need to
be watered -- or mowed. Soon, I'll replace the roof and repaint
the house exterior -- those will be the last "big" chores I
intend to tackle.

(Well, I also have to haul 20T of stone into the back yard -- but,
I built an electric wheelbarrow to make that easier)

On Sat, 28 Nov 2015 19:20:25 -0700, Don Y
wrote:

On 11/27/2015 6:16 PM, Oren wrote:
On Fri, 27 Nov 2015 16:25:17 -0700, Don Y
wrote:

On 11/27/2015 3:54 PM, Oren wrote:

I guess my point was that the irrigation line "auto" drain valve and
the solar panel "drain" valve work basically the same. Water pressure
closes them - no pressure allows them to drain, either into the soil
or into the pool. What I call, maybe not correctly a "positive" drain
valve.

Yes. But I would imagine you'd have less "problems" (hard water
encrustations) with your "set up" than the configuration that
I'm employing.

We have the hardest water in the nation. See the "Lake Mead Bath Tub
Ring".

Dunno. Half of our water is well sourced. The other half comes down a
few hundred miles of concrete aqueducts, pipes, etc.

I've not had a problem in over a decade on the solar panel
drain valve. Maybe you worry to much; regarding the irrigation "auto"
drain valves under ground. Picky picky picky.

I'm not keen on creating "maintenance tasks". E.g., I felled ALL
of the trees on the property before I got old enough to make that
a "challenge". I pulled out the lawn so it wouldn't need to
be watered -- or mowed. Soon, I'll replace the roof and repaint
the house exterior -- those will be the last "big" chores I
intend to tackle.

(Well, I also have to haul 20T of stone into the back yard -- but,
I built an electric wheelbarrow to make that easier)

I'm not sure why you worry about a"Calcification and "auto-drain"
valves?" Do you worry to much?

On 11/28/2015 7:57 PM, Oren wrote:

I'm not keen on creating "maintenance tasks". E.g., I felled ALL
of the trees on the property before I got old enough to make that
a "challenge". I pulled out the lawn so it wouldn't need to
be watered -- or mowed. Soon, I'll replace the roof and repaint
the house exterior -- those will be the last "big" chores I
intend to tackle.

I'm not sure why you worry about a"Calcification and "auto-drain"
valves?" Do you worry to much?

Nope. I am just pro-active. I don't like having to "jump" to fix
something that needn't have failed. I'd rather spend time
thinking about *likely* failures and coming up with ways of
avoiding or minimizing them than to have to deal with an inevitable
failure when it is "convenient" for that *failure*, and not me!

E.g., I "rescue" a lot of LCD monitors. They're relatively inexpensive
(components) to repair. And, the effort to do so is largely
"therapeutic" -- mindless. Having opted to fix a particular monitor,
should I put "cheap" parts in it -- knowing they WILL fail in
a year or two? Or, should I spend a few pennies more to double
that life expectancy -- given that the time I invest will be the
same in each case (for this *initial* repair)?

Should I keep several monitors on hand in *repaired* state (they take
up just as much space when UNrepaired -- and, unrepaired requires no
investment of capitol or time!)? Or, repair them as/when needed?
The difference in approaches becomes apparent when someone grumbles
that *their* monitor has died (usually while they are "doing something"
that they would prefer not to "lose"). In the one case, I hand them
a replacement monitor and tell them to bring me the broken one
"when they get a chance". They go away happy and I'm glad I've helped
them. In the other case, I shrug my shoulders as it will be at
least an hour before I could conceivably repair their monitor ASSUMING
I have the parts on hand AND am willing to drop whatever I'm working
on at the time. Given that I would prefer not to have them inconvenienced,
there's a fair bit of self-imposed pressure to deal with their problem
*now* -- at the expense of my current activities.

Don Y posted for all of us...



Nope. I am just pro-active. I don't like having to "jump" to fix
something that needn't have failed. I'd rather spend time
thinking about *likely* failures and coming up with ways of
avoiding or minimizing them than to have to deal with an inevitable
failure when it is "convenient" for that *failure*, and not me!


So think about pancreatic cancer or Alzheimer's or gangrene of the gonads or
anything blue ointment ain't gonna fix.

--
Tekkie

On 11/30/2015 2:01 PM, Tekkie® wrote:
Don Y posted for all of us...

Nope. I am just pro-active. I don't like having to "jump" to fix
something that needn't have failed. I'd rather spend time
thinking about *likely* failures and coming up with ways of
avoiding or minimizing them than to have to deal with an inevitable
failure when it is "convenient" for that *failure*, and not me!

So think about pancreatic cancer or Alzheimer's or gangrene of the gonads or
anything blue ointment ain't gonna fix.

Why waste time thinking about something I can't *do* anything about?

Instead, I'll look at the likely issues that my body will face -- given
my history, lifestyle, etc. -- and proactively address those. If a
piano falls out of a 6th floor window as I'm walking under it... so be it!
(I'm not going to avoid walking near 6 story buildings on the off chance
that a piano might fall)

Watched a friend die of esophageal cancer last year; another lose her
battle to ALS; now watching one go to ovarian cancer. I'm pretty sure
none of them thought "if only I had (or hadn't!) done..."

OTOH, watched a neighbor become full-on type 2 diabetic; then have his
heart attack; then a stroke... waiting to see when he gets the message
regarding diet, weight, exercise, lifestyle, etc. Apparently not
willing to listen to his doctor's advice -- and grumbles each time
one of the MD's "predictions" comes true! :-/

: