I have a strange sounding idea. I want to have an extra compressed air
tank in my system. I have a bunch of tanks at this moment to choose
from. This way, I could run air hungry tools like breakers, etc,
intermittently but longer.

So far, so good, and nothing complicated. I have a whole bunch of
tanks right now, and thought to do something nice for my shop and have
an extra tank.

Examples of tanks I have a

http://igor.chudov.com/misc/ebay/tmp/Marengo/186.jpg
http://goo.gl/PdkzbM (Tank with "QT-15" lettering on left)

However, I also realize that with a big extra tank, it will take so
much longer for the air system to come up to pressure. This will be my
wasted money, as people will be waiting longer to use compressed air.

So, I thought, can I have a valve, that would not fill the tank, until
system pressure reached 120 PSI. And then it would shut off again if
the pressure ever falls to below 90 PSI.

To use the accumulator tank to supply air, another pipe would be used
with a check valve.

This setup makes sense to me, as

1) I would get the system to reach pressure quickly and
2) I would eventually get a supply of air in the accumulator,
without ever dropping the system pressure below 90 PSI.

I do realize that I can accomplish what I want, with a electric
pressure switch and a normally open pneumatic valve. But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?

Ignoramus5722 wrote:

I have a strange sounding idea. I want to have an extra compressed air
tank in my system. I have a bunch of tanks at this moment to choose
from. This way, I could run air hungry tools like breakers, etc,
intermittently but longer.

So far, so good, and nothing complicated. I have a whole bunch of
tanks right now, and thought to do something nice for my shop and have
an extra tank.

Examples of tanks I have a

http://igor.chudov.com/misc/ebay/tmp/Marengo/186.jpg
http://goo.gl/PdkzbM (Tank with "QT-15" lettering on left)

However, I also realize that with a big extra tank, it will take so
much longer for the air system to come up to pressure. This will be my
wasted money, as people will be waiting longer to use compressed air.

So, I thought, can I have a valve, that would not fill the tank, until
system pressure reached 120 PSI. And then it would shut off again if
the pressure ever falls to below 90 PSI.

To use the accumulator tank to supply air, another pipe would be used
with a check valve.

This setup makes sense to me, as

1) I would get the system to reach pressure quickly and
2) I would eventually get a supply of air in the accumulator,
without ever dropping the system pressure below 90 PSI.

I do realize that I can accomplish what I want, with a electric
pressure switch and a normally open pneumatic valve. But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?

Add compressor capacity, rather than tank volume, presuming you have a
reasonable size tank now. Set the pressure switch for the second
compressor to come on as say 10 psi below the first's cut in pressure so
it will only come on when the first is unable to keep up with the
demand.

Ignoramus5722 fired this volley in
:

I do realize that I can accomplish what I want, with a electric
pressure switch and a normally open pneumatic valve. But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?


Ig, you're mistaken about people "waiting for air". Unless their net
usage is higher than the pump capacity, the pump will come on when the
combined tanks get to the desired cut-in pressure, and shut off when they
get topped off, just like they do with smaller tanks. The difference is,
that they can use air-hogs longer before they have to stop.

The total duty cycle will remain approximately what it was before. The
pump will stay on longer, yes; It'll also stay off longer.

You don't need _any_ valves to accomplish what you want. You're over-
thinking it.

(although you should provide manual valves to isolate tanks, in case of a
leak or a service issue)

Lloyd

On 2013-12-07, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Ignoramus5722 fired this volley in
:

I do realize that I can accomplish what I want, with a electric
pressure switch and a normally open pneumatic valve. But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?


Ig, you're mistaken about people "waiting for air".

Unless their net usage is higher than the pump capacity, the pump
will come on when the combined tanks get to the desired cut-in
pressure, and shut off when they get topped off, just like they do
with smaller tanks. The difference is, that they can use air-hogs
longer before they have to stop.

We do not have the compressor on at all times. We turn it on in the
morning or when it is necessary.

The total duty cycle will remain approximately what it was before. The
pump will stay on longer, yes; It'll also stay off longer.

Exactly.

But when we turn the compressor on in the morning, when we need air, I
do not want to wait extra 15 minutes.

You don't need _any_ valves to accomplish what you want. You're over-
thinking it.

(although you should provide manual valves to isolate tanks, in case of a
leak or a service issue)

No,I do need that for start-ups.

i

"Pete C." fired this volley in news:52a27f48$0$47806
:

Add compressor capacity, rather than tank volume, presuming you have a
reasonable size tank now.

Yep, Ig. Remember, no matter HOW large your tank, you can never use more
air per minute - on average - than your pump will supply.

LLoyd

On 2013-12-07, Pete C. wrote:
Add compressor capacity, rather than tank volume, presuming you have a
reasonable size tank now. Set the pressure switch for the second
compressor to come on as say 10 psi below the first's cut in pressure so
it will only come on when the first is unable to keep up with the
demand.

Pete, I would like to explore my idea in the original post, for now. I
do not really want to get more compressors, for now. Even though it is
tempting to upgrade,I just bought a 15HP Quincy 370 compressor. My
shop guy wants me to upgrade my 10HP quincy to this one.But I do not
want the hassle of upgrading the wiring and dealing with a messy
wiring duct.

i

.... But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?

It's a pressure relief valve. With an exit port, not just venting to
air. The tricky part is finding one with an adjustable differential, so
that it could be made to stay open until 90 psi. Bob

On 2013-12-07, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
"Pete C." fired this volley in news:52a27f48$0$47806
:

Add compressor capacity, rather than tank volume, presuming you have a
reasonable size tank now.

Yep, Ig. Remember, no matter HOW large your tank, you can never use more
air per minute - on average - than your pump will supply.

Lloyd, and Pete, I appreciate your opinion and I do understand that I
cannot get more compressed air per hour with an extra tank.

But, I want an answer to my originalquestion,as I do see a big benefit
in what I want to accomplish.

i

Ignoramus5722 fired this volley in
news
But, I want an answer to my originalquestion,as I do see a big benefit
in what I want to accomplish.


Ok... just put a uni-directional flow-control valve (with a ball check in
it) between the 'main system' and the reserve tank. Control the flow
(slow bleed) INTO the reserve tank, but let it back-flow freely into the
main system any time its pressure is greater than the system.

Then the main system will pump up _almost_ as fast as it would without
the reserve, slowly bleeding air into the reserve as it goes. When
sudden demands occur, the reserve will freely feed the whole system.

Such valves are purely mechanical, one-piece assemblies... ball-check and
flow control (often needle type) valve in one unit.

Lloyd

Bob Engelhardt fired this volley in
:

It's a pressure relief valve. With an exit port, not just venting to
air. The tricky part is finding one with an adjustable differential, so
that it could be made to stay open until 90 psi. Bob

That doesn't solve the filling part, only the 'feeding' part.

A one-direction flow control valve will do both.

Lloyd

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com fired this volley in
.70:




Here's one that'll do 83scfm in the free-flow direction, and the schematic
symbol.

http://www.mcmaster.com/#45045k44/=pp43sh

LLoyd

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com fired this volley in
. 3.70:

http://www.mcmaster.com/#45045k44/=pp43sh

Oh... that one is a poppet style, not ball-check, but I've used that model,
and they last for years and years.

Lloyd

On 12/6/2013 9:28 PM, Lloyd E. Sponenburgh wrote:
Bob fired this volley in
:

It's a pressure relief valve. With an exit port, not just venting to
air. The tricky part is finding one with an adjustable differential, so
that it could be made to stay open until 90 psi. Bob

That doesn't solve the filling part, only the 'feeding' part.

A one-direction flow control valve will do both.

Lloyd

Yeah, it does: the relief valve "in" is connected to the basic tank and
the "out" to the auxiliary tank. When the basic tank reaches 125, the
relief valve opens & delivers air to the aux tank.

Unless I'm missing something, which wouldn't be the first time.

Bob

Bob Engelhardt fired this volley in
:

Yeah, it does: the relief valve "in" is connected to the basic tank and
the "out" to the auxiliary tank. When the basic tank reaches 125, the
relief valve opens & delivers air to the aux tank.

Unless I'm missing something, which wouldn't be the first time.

And when that 90psi relief valve opens, it supplies 125psi MINUS 90 to
the reserve -- 35psi. And how's all that 35psi air going to get back to
the system FROM the aux tank when needed?

A simple check valve with one-direction restriction fixes the whole
problem -- both ways, and without any pressure differentials (well, a
pound or two).

Lloyd

On 12/6/2013 9:51 PM, Lloyd E. Sponenburgh wrote:
....
And when that 90psi relief valve opens, it supplies 125psi MINUS 90...

Oooh ... yeah. Feeling dumb, Bob

On 2013-12-07, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com fired this volley in
. 3.70:

http://www.mcmaster.com/#45045k44/=pp43sh

Oh... that one is a poppet style, not ball-check, but I've used that model,
and they last for years and years.

Lloyd

Lloyd, I thought a lot about this, and I think that it is the best
solution because it is so simple, and also is friendly to the air
dryer that would be between the compressor and the additional tank.

Thank you. I Saved your suggestion. I will talk to my shop guy and if
I put in the second tank, I will use this valve.

i

On Fri, 06 Dec 2013 20:03:43 -0600, Ignoramus5722
wrote:

On 2013-12-07, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Ignoramus5722 fired this volley in
:

I do realize that I can accomplish what I want, with a electric
pressure switch and a normally open pneumatic valve. But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?


Ig, you're mistaken about people "waiting for air".

Unless their net usage is higher than the pump capacity, the pump
will come on when the combined tanks get to the desired cut-in
pressure, and shut off when they get topped off, just like they do
with smaller tanks. The difference is, that they can use air-hogs
longer before they have to stop.

We do not have the compressor on at all times. We turn it on in the
morning or when it is necessary.

The total duty cycle will remain approximately what it was before. The
pump will stay on longer, yes; It'll also stay off longer.

Exactly.

But when we turn the compressor on in the morning, when we need air, I
do not want to wait extra 15 minutes.

So isolate a smaller tank before the large and use a ball valve to
shut down the main tank and use the smaller one for quick air needs.
It could easily be valved both to the compressor and to system air,
with a single line for your immediate use. Keep the little guy filled
and only open him when you need a dustoff.


--
Make awkward sexual advances, not war.

On 2013-12-07, Bob Engelhardt wrote:
... But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?

It's a pressure relief valve. With an exit port, not just venting to
air. The tricky part is finding one with an adjustable differential, so
that it could be made to stay open until 90 psi. Bob

Bob, does that valve waste a lot of energy, meaning does it have a big
pressure drop?

i

i

If you find a good solution, please let me know. I bring a tractor PTO
compressor out to the field every day. I could reduce the tractor RPM
(save fuel) if such an accumulator could be designed.

I've thought of adding a couple old 100 lb. LP bottles but don't want
to wait for the whole system to build pressure before starting. The
shears need 100 psi to work so you can't start until almost to cutout
pressure.

Karl

On 2013-12-07, Karl Townsend wrote:

i

If you find a good solution, please let me know. I bring a tractor PTO
compressor out to the field every day. I could reduce the tractor RPM
(save fuel) if such an accumulator could be designed.

I've thought of adding a couple old 100 lb. LP bottles but don't want
to wait for the whole system to build pressure before starting. The
shears need 100 psi to work so you can't start until almost to cutout
pressure.

Karl


Karl, I am still thinking. Yesterday I thought to go with what Lloyd
recommended, a flow control valve. Then I realized that it is not as
good as I want. There is an energy loss and also the system will not
come up to pressure fast.

Nw I am leaning towards a system with a check valve for air outflow,
and a pressure switch controlled solenoid valve for filling.

i

On Sat, 07 Dec 2013 07:39:52 -0600, Ignoramus5722
wrote:

On 2013-12-07, Karl Townsend wrote:

i

If you find a good solution, please let me know. I bring a tractor PTO
compressor out to the field every day. I could reduce the tractor RPM
(save fuel) if such an accumulator could be designed.

I've thought of adding a couple old 100 lb. LP bottles but don't want
to wait for the whole system to build pressure before starting. The
shears need 100 psi to work so you can't start until almost to cutout
pressure.

Karl


Karl, I am still thinking. Yesterday I thought to go with what Lloyd
recommended, a flow control valve. Then I realized that it is not as
good as I want. There is an energy loss and also the system will not
come up to pressure fast.

Nw I am leaning towards a system with a check valve for air outflow,
and a pressure switch controlled solenoid valve for filling.

i

Ig, if the main problem is the time it takes to come up to pressure in
the morning, a timer relay to start the compressor 15 min. early could
do it. Or fix all your leaks and unplug or block quick connects when
leaving, and leave the compressor up at night. With no consumption,
it won't run.

Pete Keillor

Karl Townsend wrote:

i

If you find a good solution, please let me know. I bring a tractor PTO
compressor out to the field every day. I could reduce the tractor RPM
(save fuel) if such an accumulator could be designed.

I've thought of adding a couple old 100 lb. LP bottles but don't want
to wait for the whole system to build pressure before starting. The
shears need 100 psi to work so you can't start until almost to cutout
pressure.

Karl

How much volume do you need? I would think that a basic gas engine
powered compressor (with throttle control) mounted on a 3pt skid would
be more fuel efficient than running a large tractor at high idle. Since
that compressor has a tank, it should retain pressure between uses so
the startup fill time would be minimal.

On 2013-12-07, Pete Keillor wrote:
On Sat, 07 Dec 2013 07:39:52 -0600, Ignoramus5722
wrote:

On 2013-12-07, Karl Townsend wrote:

i

If you find a good solution, please let me know. I bring a tractor PTO
compressor out to the field every day. I could reduce the tractor RPM
(save fuel) if such an accumulator could be designed.

I've thought of adding a couple old 100 lb. LP bottles but don't want
to wait for the whole system to build pressure before starting. The
shears need 100 psi to work so you can't start until almost to cutout
pressure.

Karl


Karl, I am still thinking. Yesterday I thought to go with what Lloyd
recommended, a flow control valve. Then I realized that it is not as
good as I want. There is an energy loss and also the system will not
come up to pressure fast.

Nw I am leaning towards a system with a check valve for air outflow,
and a pressure switch controlled solenoid valve for filling.

i

Ig, if the main problem is the time it takes to come up to pressure in
the morning, a timer relay to start the compressor 15 min. early could
do it. Or fix all your leaks and unplug or block quick connects when
leaving, and leave the compressor up at night. With no consumption,
it won't run.

Pete, there are days when we do not need the compressor. I do not want
to start it on a timer.

i

Ignoramus31823 wrote:

On 2013-12-07, Pete Keillor wrote:
On Sat, 07 Dec 2013 07:39:52 -0600, Ignoramus5722
wrote:

On 2013-12-07, Karl Townsend wrote:

i

If you find a good solution, please let me know. I bring a tractor PTO
compressor out to the field every day. I could reduce the tractor RPM
(save fuel) if such an accumulator could be designed.

I've thought of adding a couple old 100 lb. LP bottles but don't want
to wait for the whole system to build pressure before starting. The
shears need 100 psi to work so you can't start until almost to cutout
pressure.

Karl


Karl, I am still thinking. Yesterday I thought to go with what Lloyd
recommended, a flow control valve. Then I realized that it is not as
good as I want. There is an energy loss and also the system will not
come up to pressure fast.

Nw I am leaning towards a system with a check valve for air outflow,
and a pressure switch controlled solenoid valve for filling.

i

Ig, if the main problem is the time it takes to come up to pressure in
the morning, a timer relay to start the compressor 15 min. early could
do it. Or fix all your leaks and unplug or block quick connects when
leaving, and leave the compressor up at night. With no consumption,
it won't run.

Pete, there are days when we do not need the compressor. I do not want
to start it on a timer.

i

Shut off the main valve at the tank when you leave for the day,
isolating any leaks in your distribution piping. When you do need air,
open the valve and it only needs to fill the relatively small volume of
the distribution piping. If your compressor tank and pump leak a lot you
need to fix that.

"Ignoramus5722" wrote in message
...
On 2013-12-07, Bob Engelhardt wrote:
... But I thought,
perhaps, there is a purely pneumatic valve that does this? What
would
it be called?

It's a pressure relief valve. With an exit port, not just venting
to
air. The tricky part is finding one with an adjustable
differential, so
that it could be made to stay open until 90 psi. Bob

Bob, does that valve waste a lot of energy, meaning does it have a
big
pressure drop?

i

I'd start with a semiautomatic system, separate manual shutoff valves
on the inlets to the small and large tanks and a check valve that lets
the large tank flow into the small one.

When you turn the compressor on set the valves to fill only the small
tank, so you have pressure quickly.

When you know you will need more volume close the intake to the small
tank and let the compressor fill the large tank directly. The small
tank will supply immediate needs while the large one fills
efficiently, without wastefull pressure drops. Once the large one is
up the check valve will keep the small tank full if you forget to
reopen its intake valve.

If that plan works out you could automate it with a valve operated by
the pressure in the small tank. Then a high demand while the large
tank is still filling will switch the compressor back to the small
tank.

Looking for a good example of a pressure-actuated multiport valve is
too tedious on my dial-up. This should get you started.
https://controls.engin.umich.edu/wik...TypesSelection

jsw

On Sat, 07 Dec 2013 07:39:52 -0600, Ignoramus5722
wrote:

On 2013-12-07, Karl Townsend wrote:

i

If you find a good solution, please let me know. I bring a tractor PTO
compressor out to the field every day. I could reduce the tractor RPM
(save fuel) if such an accumulator could be designed.

I've thought of adding a couple old 100 lb. LP bottles but don't want
to wait for the whole system to build pressure before starting. The
shears need 100 psi to work so you can't start until almost to cutout
pressure.

Karl


Karl, I am still thinking. Yesterday I thought to go with what Lloyd
recommended, a flow control valve. Then I realized that it is not as
good as I want. There is an energy loss and also the system will not
come up to pressure fast.

Nw I am leaning towards a system with a check valve for air outflow,
and a pressure switch controlled solenoid valve for filling.

i
If a valve opens and the flow is large enough through the valve then
suddenly there will be a pressure drop in the whole system. The drop
depends on how much pressure is in the extra tank when the valve opens
and how big it is in relation the the regular tank.
Eric

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"Jim Wilkins" wrote in message
...


I'd start with a semiautomatic system, separate manual shutoff
valves on the inlets to the small and large tanks and a check valve
that lets the large tank flow into the small one....
jsw

If you already have a check valve going into the small tank it doesn't
need a shutoff. The check valve will keep air in the small tank when
you open the valve to fill the large one.
jsw

On Fri, 06 Dec 2013 20:52:04 -0500, "Pete C."
wrote:


Ignoramus5722 wrote:

I have a strange sounding idea. I want to have an extra compressed air
tank in my system. I have a bunch of tanks at this moment to choose
from. This way, I could run air hungry tools like breakers, etc,
intermittently but longer.

So far, so good, and nothing complicated. I have a whole bunch of
tanks right now, and thought to do something nice for my shop and have
an extra tank.

Examples of tanks I have a

http://igor.chudov.com/misc/ebay/tmp/Marengo/186.jpg
http://goo.gl/PdkzbM (Tank with "QT-15" lettering on left)

However, I also realize that with a big extra tank, it will take so
much longer for the air system to come up to pressure. This will be my
wasted money, as people will be waiting longer to use compressed air.

So, I thought, can I have a valve, that would not fill the tank, until
system pressure reached 120 PSI. And then it would shut off again if
the pressure ever falls to below 90 PSI.

To use the accumulator tank to supply air, another pipe would be used
with a check valve.

This setup makes sense to me, as

1) I would get the system to reach pressure quickly and
2) I would eventually get a supply of air in the accumulator,
without ever dropping the system pressure below 90 PSI.

I do realize that I can accomplish what I want, with a electric
pressure switch and a normally open pneumatic valve. But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?

Add compressor capacity, rather than tank volume, presuming you have a
reasonable size tank now. Set the pressure switch for the second
compressor to come on as say 10 psi below the first's cut in pressure so
it will only come on when the first is unable to keep up with the
demand.

Absolutely! Good answer! Only answer!

Gunner, who does commercial air compressors and systems



--
"Owning a sailboat is like marrying a nymphomaniac. You don’t want to do that
but it is great if your best friend does. That way you get all the benefits without any of the upkeep"

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On Fri, 06 Dec 2013 20:06:57 -0600, Ignoramus5722
wrote:

On 2013-12-07, Pete C. wrote:
Add compressor capacity, rather than tank volume, presuming you have a
reasonable size tank now. Set the pressure switch for the second
compressor to come on as say 10 psi below the first's cut in pressure so
it will only come on when the first is unable to keep up with the
demand.

Pete, I would like to explore my idea in the original post, for now. I
do not really want to get more compressors, for now. Even though it is
tempting to upgrade,I just bought a 15HP Quincy 370 compressor. My
shop guy wants me to upgrade my 10HP quincy to this one.But I do not
want the hassle of upgrading the wiring and dealing with a messy
wiring duct.

i
Whats your current wire size? How far is the run?

Gunner

--
"Owning a sailboat is like marrying a nymphomaniac. You don’t want to do that
but it is great if your best friend does. That way you get all the benefits without any of the upkeep"

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

On Fri, 06 Dec 2013 19:54:26 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Ignoramus5722 fired this volley in
m:

I do realize that I can accomplish what I want, with a electric
pressure switch and a normally open pneumatic valve. But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?


Ig, you're mistaken about people "waiting for air". Unless their net
usage is higher than the pump capacity, the pump will come on when the
combined tanks get to the desired cut-in pressure, and shut off when they
get topped off, just like they do with smaller tanks. The difference is,
that they can use air-hogs longer before they have to stop.

The total duty cycle will remain approximately what it was before. The
pump will stay on longer, yes; It'll also stay off longer.

You don't need _any_ valves to accomplish what you want. You're over-
thinking it.

(although you should provide manual valves to isolate tanks, in case of a
leak or a service issue)

Lloyd

ABSOLUTELY!!


--
"Owning a sailboat is like marrying a nymphomaniac. You don’t want to do that
but it is great if your best friend does. That way you get all the benefits without any of the upkeep"

---
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http://www.avast.com

On 2013-12-07, wrote:
On Sat, 07 Dec 2013 07:39:52 -0600, Ignoramus5722
wrote:

On 2013-12-07, Karl Townsend wrote:

i

If you find a good solution, please let me know. I bring a tractor PTO
compressor out to the field every day. I could reduce the tractor RPM
(save fuel) if such an accumulator could be designed.

I've thought of adding a couple old 100 lb. LP bottles but don't want
to wait for the whole system to build pressure before starting. The
shears need 100 psi to work so you can't start until almost to cutout
pressure.

Karl


Karl, I am still thinking. Yesterday I thought to go with what Lloyd
recommended, a flow control valve. Then I realized that it is not as
good as I want. There is an energy loss and also the system will not
come up to pressure fast.

Nw I am leaning towards a system with a check valve for air outflow,
and a pressure switch controlled solenoid valve for filling.

i
If a valve opens and the flow is large enough through the valve then
suddenly there will be a pressure drop in the whole system. The drop
depends on how much pressure is in the extra tank when the valve opens
and how big it is in relation the the regular tank.
Eric

Right. But I can deal with that. It is not a big factor.

i

On 2013-12-07, Gunner Asch wrote:
On Fri, 06 Dec 2013 20:06:57 -0600, Ignoramus5722
wrote:

On 2013-12-07, Pete C. wrote:
Add compressor capacity, rather than tank volume, presuming you have a
reasonable size tank now. Set the pressure switch for the second
compressor to come on as say 10 psi below the first's cut in pressure so
it will only come on when the first is unable to keep up with the
demand.

Pete, I would like to explore my idea in the original post, for now. I
do not really want to get more compressors, for now. Even though it is
tempting to upgrade,I just bought a 15HP Quincy 370 compressor. My
shop guy wants me to upgrade my 10HP quincy to this one.But I do not
want the hassle of upgrading the wiring and dealing with a messy
wiring duct.

i
Whats your current wire size? How far is the run?


40 feet, I believe 10 gauge, 30 amp breaker, 220v

i

"Ignoramus5722" wrote in message
...

snip

This setup makes sense to me, as

1) I would get the system to reach pressure quickly and
2) I would eventually get a supply of air in the accumulator,
without ever dropping the system pressure below 90 PSI.

I do realize that I can accomplish what I want, with a electric
pressure switch and a normally open pneumatic valve. But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?

A more complicated way... :-)

Have a pressure transducer in each tank and a solenoid valve between them.
Possibly with the flow control/check valve in line with the solenoid valve.

Transducers ran to a controller and a little software.

For this, assuming the compressor starts at or below 90PSI and Stops at or
greater than 125 PSI.

Valve = Primary_Tank_PSI Secondary_Tank_PSI OR Primary_Tank_PSI 120 //
Valve ON when secondary can help or when primary is near full

Compressor = (Compressor AND Primary_Tank_PSI 125) OR (NOT Compressor and
Primary_Tank_PSI = 90) // Compressor turns ON at 90 PSI and OFF at 125
PSI.

RogerN

On 2013-12-07, RogerN wrote:
"Ignoramus5722" wrote in message
...

snip

This setup makes sense to me, as

1) I would get the system to reach pressure quickly and
2) I would eventually get a supply of air in the accumulator,
without ever dropping the system pressure below 90 PSI.

I do realize that I can accomplish what I want, with a electric
pressure switch and a normally open pneumatic valve. But I thought,
perhaps, there is a purely pneumatic valve that does this? What would
it be called?

A more complicated way... :-)

Have a pressure transducer in each tank and a solenoid valve between them.
Possibly with the flow control/check valve in line with the solenoid valve.

Transducers ran to a controller and a little software.

For this, assuming the compressor starts at or below 90PSI and Stops at or
greater than 125 PSI.

Valve = Primary_Tank_PSI Secondary_Tank_PSI OR Primary_Tank_PSI 120 //
Valve ON when secondary can help or when primary is near full

Compressor = (Compressor AND Primary_Tank_PSI 125) OR (NOT Compressor and
Primary_Tank_PSI = 90) // Compressor turns ON at 90 PSI and OFF at 125
PSI.

RogerN



Roger, this is what I may end up doing, except no software is
needed. All that is needed is a compressor pressure switch and a NC
relay.

i

Ignoramus31823 fired this volley in
:

i


I still want to know why the check/flow would:
1) Cause the system to take (much) longer to pump up, and
2) "Waste energy".

If you install a check valve/flow-control between the two tanks, so that
the reserve tank can only be filled through a small restriction, but can
dump instantly, any time its pressure is higher than 'system', then
where's the loss?

The small tank will pump up in about the same time as before, with the
only 'loss' being the small flow into the larger tank. The big tank comes
up to system pressure slowly; and as slowly as you want. Then, if you
demand more than the small tank can provide, the reserve will dump
_freely_ (without any significant pressure loss - maybe 1/2 psi) back
into the system.

This is a pretty common way to provide reserve short-term capacity
without increasing pump capacity.
???

So, (I mean it) please describe the problems so I can critique the method
myself. I just don't see the losses or problems you describe.

LLoyd

On Sat, 07 Dec 2013 04:55:09 -0500, Karl Townsend
wrote:


i

If you find a good solution, please let me know. I bring a tractor PTO
compressor out to the field every day. I could reduce the tractor RPM
(save fuel) if such an accumulator could be designed.

I've thought of adding a couple old 100 lb. LP bottles but don't want
to wait for the whole system to build pressure before starting. The
shears need 100 psi to work so you can't start until almost to cutout
pressure.

Karl

With air compressors..there is going to be wait time..unless you
manage to come up with a screw compressor.....and then there will be
reserve fill time. Fact of life.


--
"Owning a sailboat is like marrying a nymphomaniac. You don’t want to do that
but it is great if your best friend does. That way you get all the benefits without any of the upkeep"

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On Sat, 07 Dec 2013 09:27:46 -0600, Ignoramus31823
wrote:

On 2013-12-07, Pete Keillor wrote:
On Sat, 07 Dec 2013 07:39:52 -0600, Ignoramus5722
wrote:

On 2013-12-07, Karl Townsend wrote:

i

If you find a good solution, please let me know. I bring a tractor PTO
compressor out to the field every day. I could reduce the tractor RPM
(save fuel) if such an accumulator could be designed.

I've thought of adding a couple old 100 lb. LP bottles but don't want
to wait for the whole system to build pressure before starting. The
shears need 100 psi to work so you can't start until almost to cutout
pressure.

Karl


Karl, I am still thinking. Yesterday I thought to go with what Lloyd
recommended, a flow control valve. Then I realized that it is not as
good as I want. There is an energy loss and also the system will not
come up to pressure fast.

Nw I am leaning towards a system with a check valve for air outflow,
and a pressure switch controlled solenoid valve for filling.

i

Ig, if the main problem is the time it takes to come up to pressure in
the morning, a timer relay to start the compressor 15 min. early could
do it. Or fix all your leaks and unplug or block quick connects when
leaving, and leave the compressor up at night. With no consumption,
it won't run.

Pete, there are days when we do not need the compressor. I do not want
to start it on a timer.

i

If you have no leaks.the timer may kick..but if the pressure is still
up..it wont run.

Gunner

--
"Owning a sailboat is like marrying a nymphomaniac. You don’t want to do that
but it is great if your best friend does. That way you get all the benefits without any of the upkeep"

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On Sat, 07 Dec 2013 14:17:14 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Ignoramus31823 fired this volley in
m:

i


I still want to know why the check/flow would:
1) Cause the system to take (much) longer to pump up, and
2) "Waste energy".

If you install a check valve/flow-control between the two tanks, so that
the reserve tank can only be filled through a small restriction, but can
dump instantly, any time its pressure is higher than 'system', then
where's the loss?

The small tank will pump up in about the same time as before, with the
only 'loss' being the small flow into the larger tank. The big tank comes
up to system pressure slowly; and as slowly as you want. Then, if you
demand more than the small tank can provide, the reserve will dump
_freely_ (without any significant pressure loss - maybe 1/2 psi) back
into the system.

This is a pretty common way to provide reserve short-term capacity
without increasing pump capacity.
???

So, (I mean it) please describe the problems so I can critique the method
myself. I just don't see the losses or problems you describe.

LLoyd

The loss is a consequence of the delta P across the adjustable orifice
in the flow-check. But my gut feeling is that, if the system is used
and described, the loss will be insignificant compared to the effort
and expense required to eliminate it.

--
Ned Simmons

On 2013-12-07, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Ignoramus31823 fired this volley in
:

i


I still want to know why the check/flow would:
1) Cause the system to take (much) longer to pump up, and
2) "Waste energy".

If you install a check valve/flow-control between the two tanks, so that
the reserve tank can only be filled through a small restriction, but can
dump instantly, any time its pressure is higher than 'system', then
where's the loss?

The small tank will pump up in about the same time as before, with the
only 'loss' being the small flow into the larger tank. The big tank comes
up to system pressure slowly; and as slowly as you want. Then, if you
demand more than the small tank can provide, the reserve will dump
_freely_ (without any significant pressure loss - maybe 1/2 psi) back
into the system.

This is a pretty common way to provide reserve short-term capacity
without increasing pump capacity.
???

So, (I mean it) please describe the problems so I can critique the method
myself. I just don't see the losses or problems you describe.

If the "loss" that occurs during initial pumping up is small, then the
tank is slow to fill, and it means that it will not be filled fast
when the system reaches pressure.

i

On Sat, 07 Dec 2013 13:21:49 -0600, Ignoramus31823
wrote:

On 2013-12-07, Gunner Asch wrote:
On Fri, 06 Dec 2013 20:06:57 -0600, Ignoramus5722
wrote:

On 2013-12-07, Pete C. wrote:
Add compressor capacity, rather than tank volume, presuming you have a
reasonable size tank now. Set the pressure switch for the second
compressor to come on as say 10 psi below the first's cut in pressure so
it will only come on when the first is unable to keep up with the
demand.

Pete, I would like to explore my idea in the original post, for now. I
do not really want to get more compressors, for now. Even though it is
tempting to upgrade,I just bought a 15HP Quincy 370 compressor. My
shop guy wants me to upgrade my 10HP quincy to this one.But I do not
want the hassle of upgrading the wiring and dealing with a messy
wiring duct.

i
Whats your current wire size? How far is the run?


40 feet, I believe 10 gauge, 30 amp breaker, 220v

i

Right at the border for a intermitant load. Drop it to 8 ga and put in
a 60 amp breaker and you are golden. Im sure you can come up with
120' of 8 gage while you are closing down factories.


--
"Owning a sailboat is like marrying a nymphomaniac. You don’t want to do that
but it is great if your best friend does. That way you get all the benefits without any of the upkeep"

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