Back Flow Preventer - Strange Noise Drip System

[electronman1729]

So my back flow preventer started making a strange sound when my drip irrigation system turns on. Any ideas?

Never did this before.

[GeorgeandSugar]

What is the sound that it is making?


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[ben4372]

A squeal or a hiss. Or a shuddery sound. By all accounts something is amiss.

I would take it apart ad see if everything looks proper. If it looks good, use some special sprinkler grease and see what happens. Might get a rebuild kit just because. Could also be a valve not totally closing and you have a small amount of water still flowing through the valve. That can make funny sounds. The beauty of sprinkler parts is they have the shelf like of yogurt. I had to replace a valve this year. A different on last year. A few heads the year before. Good thing sprinkler parts are cheap.

Two years ago I started removing my back flow device and taking it inside. Draining and blowing out didn't work a couple times. So now I take the whole thing inside.

[DEAGLER]

You sure its not the valves making noise? Had a customer’s valve keep hissing even though it was off. Changed the diaphragm assembly and still did it. End up having to replace the whole valve.

[electronman1729]

Its only the drip system that does this.

I would say a shuddery sound.

Its coming from the back flow preventer

[Wulf202]

replace the drip system solenoid guts and top half, it's likely weak and will only cost a few dollars. Just buy a new matching valve and swap 4 screws and 2 wires. Once in a while a bad one will make pipes sing at a large fitting. Also do you mean backflow on the main or vacuum break on the sprinkler system?

[BPTactical]

The drip system is low flow. It does not cause sufficient flow/differential pressure to lift the back flow poppet valve / piston completely clear of the seat. What you are hearing is "flutter" of the valve.
As noted check downstream of the back flow preventer for restrictions.

[SideShow Bob]

The drip system is low flow. It does not cause sufficient flow/differential pressure to lift the back flow poppet valve / piston completely clear of the seat. What you are hearing is "flutter" of the valve.
As noted check downstream of the back flow preventer for restrictions.

^^This^^^

Not only is Bert a hell of a gun Smiff, he is also an expert when it comes to back flow...........

Ask him about when I hit a 4” irrigation line for the landscaping in the I-25 & Colfax interchange.

[Great-Kazoo]

^^This^^^

Not only is Bert a hell of a gun Smiff, he is also an expert when it comes to back flow...........

Ask him about when I hit a 4” irrigation line for the landscaping in the I-25 & Colfax interchange.

At his age there's probably more than "back flow" going on. .

















If you know what i mean.

[10x]

These valves are nuisance. I have a fairway valve that has a plastic disc. The disc or the gasket on the disc will fail without notice with water shoot out the valve cap. It usually happens when i a m out of town. The cap over the disc has proprietary threads or i would put on a solid cap and eliminate the disc.