Can I use a continuous pressure double check valve when connecting my sprinkler system to my water line, such as this???

http://www.watts.com/pdf/ES-9DM3_M2.pdf

I've been recommended an Anti-siphon pressure vacuum breaker, such as:

http://www.watts.com/pdf/ES-800M4QT.pdf

But they are more expensive and much bigger.

There are no city codes in my area requiring the use of a backflow prevention device though I'd still like to put something in.

Andy

ashroyer wrote:
Can I use a continuous pressure double check valve when connecting my
sprinkler system to my water line, such as this???

http://www.watts.com/pdf/ES-9DM3_M2.pdf

I've been recommended an Anti-siphon pressure vacuum breaker, such as:

http://www.watts.com/pdf/ES-800M4QT.pdf

But they are more expensive and much bigger.

There are no city codes in my area requiring the use of a backflow
prevention device though I'd still like to put something in.

Andy


--
ashroyer


Andy-

In all my spronkler vavle installtions I have used individual Champion
anit-siphon valves
rather than an input line anti-siphon device.

http://www.championirrigation.com/HT.../Cat_ASVs.html

brass on brass.............valves installed 20 years ago still working,
some solenoids replaced

That said, I cannot see why the valve you propose would not work.

However examaning the pressure drop vs flow curves that you provided,
I see that "your device" has a much larger pressure drop for a given
flow

~15psi drop at 10gpm vs ~5psi for the "other type"


depends on your flow your system requires & how much pressure you can
afford to lose.

cheers
Bob

ashroyer wrote:
Can I use a continuous pressure double check valve when connecting my
sprinkler system to my water line, such as this???

http://www.watts.com/pdf/ES-9DM3_M2.pdf

I've been recommended an Anti-siphon pressure vacuum breaker, such as:

http://www.watts.com/pdf/ES-800M4QT.pdf

But they are more expensive and much bigger.

There are no city codes in my area requiring the use of a backflow
prevention device though I'd still like to put something in.

Andy


--
ashroyer


Andy-

In all my spronkler vavle installtions I have used individual Champion
anit-siphon valves
rather than an input line anti-siphon device.

http://www.championirrigation.com/HT.../Cat_ASVs.html

brass on brass.............valves installed 20 years ago still working,
some solenoids replaced

That said, I cannot see why the valve you propose would not work.

However examaning the pressure drop vs flow curves that you provided,
I see that "your device" has a much larger pressure drop for a given
flow

~15psi drop at 10gpm vs ~5psi for the "other type"


depends on your flow your system requires & how much pressure you can
afford to lose.

cheers
Bob

The headings on the manufacturers pages clearly state that the double check
valve is not intended for health hazard applications. I would consider water
from the lawn being in my water lines a health hazard. I agree that it looks
like the check valve would be better than nothing but is not the best
reasonably available protection. I feel sure that codes require the siphon
breaker and, despite many peoples opinions, have valid reasons for doing so.
Codes are for protection against obvious and non-obvious hazards and
compliance is always a good idea, whether there is enforcement or not. Kinda
like stopping for traffic signals when no policeman is in sight

Just my opinion, others will disagree, and it's your decision.
Don Young
"ashroyer" wrote in message
...

Can I use a continuous pressure double check valve when connecting my
sprinkler system to my water line, such as this???

http://www.watts.com/pdf/ES-9DM3_M2.pdf

I've been recommended an Anti-siphon pressure vacuum breaker, such as:

http://www.watts.com/pdf/ES-800M4QT.pdf

But they are more expensive and much bigger.

There are no city codes in my area requiring the use of a backflow
prevention device though I'd still like to put something in.

Andy


--
ashroyer

On Tue, 4 Apr 2006 18:35:24 +0100, ashroyer
wrote:


Can I use a continuous pressure double check valve when connecting my
sprinkler system to my water line, such as this???

http://www.watts.com/pdf/ES-9DM3_M2.pdf

I've been recommended an Anti-siphon pressure vacuum breaker, such as:

http://www.watts.com/pdf/ES-800M4QT.pdf

But they are more expensive and much bigger.

There are no city codes in my area requiring the use of a backflow
prevention device though I'd still like to put something in.


Don't Anti-Siphon and Check Valves do different things?

If I understand it right, an anti-siphon valve allows
air INTO your hose/pipe when it demands more water than
you can supply, which keeps it from either (A) collapsing
your hose/pipe or (B) Sucking water backwards out of other
branches of your water system. Whereas a
check-valve/backflow arrestor keeps water from running
backwards in your hose/pipe when you get negative pressure.

It wouldn't hurt to have both.

"Goedjn" wrote in message
...
On Tue, 4 Apr 2006 18:35:24 +0100, ashroyer
wrote:


Can I use a continuous pressure double check valve when connecting my
sprinkler system to my water line, such as this???

http://www.watts.com/pdf/ES-9DM3_M2.pdf

I've been recommended an Anti-siphon pressure vacuum breaker, such as:

http://www.watts.com/pdf/ES-800M4QT.pdf

But they are more expensive and much bigger.

There are no city codes in my area requiring the use of a backflow
prevention device though I'd still like to put something in.


Don't Anti-Siphon and Check Valves do different things?

If I understand it right, an anti-siphon valve allows
air INTO your hose/pipe when it demands more water than
you can supply, which keeps it from either (A) collapsing
your hose/pipe or (B) Sucking water backwards out of other
branches of your water system. Whereas a
check-valve/backflow arrestor keeps water from running
backwards in your hose/pipe when you get negative pressure.

It wouldn't hurt to have both.



You're right about the check valve being one way but an anti siphon valve
simply prevents water from moving backwards when a vacuum develops in the
supply line. (this should only happen if the main water supply were shut
off and the sprinkler valve were still open). In this case, a flapper valve
opens and lets air enter the supply pipe instead of siphoning water out of
the sprinkler pipe itself.

A check valve is not perfect, some water may leak backward in a worn valve.
Since water is in contact with both sides of the valve, bacteria can migrate
upstream, this is the health concern. In the anti siphon valve, an air gap
is created segregating the grey water from the supply.

"ashroyer" wrote in message
http://www.watts.com/pdf/ES-800M4QT.pdf

But they are more expensive and much bigger.

There are no city codes in my area requiring the use of a backflow
prevention device though I'd still like to put something in.

The purpose of a bfp device is to avoid contamination of the water supply.
Forget codes. If there was a backflow just after you fertilize the lawn,
your house is the first to be contaminated. Still want to save a few bucks?

If you can afford to put in a sprinkler system and have a fancy lawn, don't
be a cheap prick when it comes to protecting your family. Use the right
device.

Edwin Pawlowski wrote:
"ashroyer" wrote in message
http://www.watts.com/pdf/ES-800M4QT.pdf

But they are more expensive and much bigger.

There are no city codes in my area requiring the use of a backflow
prevention device though I'd still like to put something in.

The purpose of a bfp device is to avoid contamination of the water supply.
Forget codes. If there was a backflow just after you fertilize the lawn,
your house is the first to be contaminated. Still want to save a few bucks?

If you can afford to put in a sprinkler system and have a fancy lawn, don't
be a cheap prick when it comes to protecting your family. Use the right
device.

I agree. Plus, when you go to sell the house, this is something that
is likely to get flagged by a home inspector, even if local codes don't
require it. For a lower price, it appears the ones he's looking at
are brass. There are plastic versions available which are lower cost
and what I would use.

wrote:


I agree. Plus, when you go to sell the house, this is something that
is likely to get flagged by a home inspector, even if local codes don't
require it. For a lower price, it appears the ones he's looking at
are brass. There are plastic versions available which are lower cost
and what I would use.


A home inspector is going to dig up the lawn lookign for one"
--
Email reply: please remove one letter from each side of "@"
Spammers are Scammers. Exterminate them.

"Doug Warner" wrote in message

A home inspector is going to dig up the lawn lookign for one"

It should be plainly visible on the feed line to the system. No digging
required.

"Edwin Pawlowski" wrote:

It should be plainly visible on the feed line to the system. No digging
required.


In my place, its buried, next to the meter, which only has the top
inch or so exposed.

--
Email reply: please remove one letter from each side of "@"
Spammers are Scammers. Exterminate them.