setting PRV and Expansion tank

[frodo]

I'm completely with you on the first comments, but lost you on PRV(pressure reducing valves) vs expansion loops. Are you implying that an expansion loop takes care of over pressurization?
Or am I misreading you again?

brain fart.i was referring to an expansion tank

 

[frodo]

typical reasons for howling are typically loose washers,or ceramic discs

 

[Diehard]

brain fart.i was referring to an expansion tank

So you were referring to an expansion "tank" when you said loop? And what did you mean when you mentioned the 6' long pipes are an expansion..."?

That was quite a brain fart you had there!

 

[frodo]

Oh, I see.
Did you ever

The water pipes supplying a water heater are typically 6' long. these pipes are an expansion loop in every sense of the word,,for a residential setting

So you were referring to an expansion "tank" when you said loop? And what did you mean when you mentioned the 6' long pipes are an expansion..."?

That was quite a brain fart you had there!

re you familiar with expansion loops?
It is an engineered offset in a piping system to give the piping a place to expand and contract due to pressure and temperature changes

 

[PlumbGate]

Oh, I see.
Did you ever experience occasional P&T relief valve discharge?
Do you have a PRV that incorporates a small thermal expansion by-pass? They apparently help but cannot be relied upon for higher rates of thermal expansion.

My house is 19 years old. 2 years ago I had a new water heater and was told it was new code to have the expansion tank so they installed it. I never had howling before the tank and filling it with air stopped the howling. Never had any discharges from anywhere in my house. And I do not know what my existing PRV incorporates.

 

[Diehard]

re you familiar with expansion loops?
It is an engineered offset in a piping system to give the piping a place to expand and contract due to pressure and temperature changes

View attachment 21126

brain fart.i was referring to an expansion tank

Now you're changing it back to an expansion loop again?
Are you serious or just playing games?
Or on drugs?

It doesn't justify an answer but yes, I have designed expansion loops for expansion and contraction of piping systems but not for the purpose of compensating for an over pressurized water system.

I'm sorry that you take offense to corrective comments. I'm not trying to be a smart *** like some people here. I really am interested in the correct answers to questions, can take corrected criticism and don't mind being proven wrong. That's how I learn.

 

[Diehard]

My house is 19 years old. 2 years ago I had a new water heater and was told it was new code to have the expansion tank so they installed it. I never had howling before the tank and filling it with air stopped the howling. Never had any discharges from anywhere in my house. And I do not know what my existing PRV incorporates.

Sounds like you were pretty fortunate.
I wish I knew what "exactly" was causing the howling. But I guess we never will.

 

[Diehard]

..

 

[PlumbGate]

Sounds like you were pretty fortunate.
I wish I knew what "exactly" was causing the howling. But I guess we never will.

Here is the original post on it.

https://www.plumbingforums.com/threads/water-pressure-too-high.13660/

 

[Diehard]

Here is the original post on it.

https://www.plumbingforums.com/threads/water-pressure-too-high.13660/

Oh yeah, I remember that.
I would suggest keeping the tank. Particularly now that you know how to recharge it.
Yes, expansion tanks have become much more common in recent years. Primarily due to the increase use of backflow preventers and pressure reducing valves.
You don't have to remove the tank, as you may have learned by now. You have a shut off valve on the cold water line that you can shut and drain enough water out of the tank to relieve any water pressure on it. That of course means opening a hot water line to allow it to drain back, unless you have an isolation valve on the Hot water line
The reason I asked as to whether your PRV included small thermal expansion by-pass is because I see that many of them do these days. I'll attach a screen copy of part of the manufacturers data sheet which talks about it. Apparently the built in thermal by-pass is capable of handling a small amount of expansion but may not be adequate to keep up with the rate of expansion. Hence the reason for the second underlined note.

 

[SGkent]

I wish I knew what "exactly" was causing the howling. But I guess we never will.

this system worked fine with no changes for about 20+ years other than a little mild hammer when the sprinklers went on or off. I guess no hammer is better but this was quite mild compared to the long foghorn. As I said - and you would have to hear it to believe me but it turns out there are two near identical howls - one is a 4 -5 second mild moan that is timed exactly when random sprinkler valves close. Just happens once in awhile but it is timed exactly to a sprinkler turning off. The other is a random always at night 10 - 20 second foghorn that sometimes has a second one about 10 seconds behind it and about 1/2 the length. Sunday night we were both standing just inside the rear slider when the long one went off. We ran out to the far corner of the house knowing we could not make it before it stopped but we waited and sure enough there was a second one about 10 seconds later. The Air conditioning compressor started vibrating and making the sound. I ran inside and flipped the temp down to see if it would start - thinking maybe a cap was going out but it fired right up. The howl / foghorn winds down at the end like it runs out of pressure. My guess is that the TEV is failing sometimes, preventing the system from releasing pressure and eventually the check valve in the compressor acts like a horn reed. Just a guess. My AC guy hasn't called back - its been 103F to 105F for the first time this year so they will be swamped with higher priority calls. Since I put the water hammer arrestor in temp where Frodo doesn't like it , the sprinklers are really quiet - so is the kitchen faucet hammer. I increased water pressure from 50 to 57 and set the ET to the same. I was going to try to start digging down to the sprinkler pipes this morning but it was 80 F and tropical muggy at 5:45 am and that makes for a miserable morning because it usually hits over 100 F by 10 am when that happens.

 

[SGkent]

dug up 8' of sprinkler line to be able to get to the bottom line, which is the supply line, tee in a fitting and install the water hammer arrestor closer to the rear sprinkler valves. To keep soil away from direct contact with it, I installed a slotted pvc pipe over it so it extends below and above the the arrestor. It is then capped to keep dirt out. This should meet Frodo's complaints.

 

[SGkent]

and today removed the water hammer on the bibb so that it can be used out front on the other sprinkler line. Back is done other than replacing pipe insulation on everything exposed.