Wouldn't matter - if you are in the right location you will hear the difference, use that method all the time to locate a problem valve anywhere on a pipe run
Water hammer from unvented cylinder
- Thread starter Taconite5
- Start date
I'll give it another go!!
If you hold it onto the pipe say a metre or 2 away and then at the valve there should be a noticeable difference.
This water hammer/pressure spikes is a bit of a mystery to me.
I have a washing machine with a 10M, 15mm (12.5mm ID) pipe run from the mains which has a DCV (double check valve) where I installed a PG today very near the DCV to take a few readings. The filling rate is a measured 8LPM and when the solenoid valve closes after filling, the PG rises from its dynamic pressure of 2.2bar to 2.7bar which is only 0.4bar above its normal static pressure of 2.3bar. Using the attached formula this means that the solenoid valve is taking 1.4 secs to close, I read that a solenoid valve will normally close in 50 millisecs, 0.05secs, if so then the pressure spike should be in the order of 11.3bar? PG ~ 13/13.5bar but I'm not getting anything remotely approaching this, maybe the flexible w/machine flexible hose is taking up the spike?. You can do your own calcs, if interested.
www.engineeringtoolbox.com
I have a washing machine with a 10M, 15mm (12.5mm ID) pipe run from the mains which has a DCV (double check valve) where I installed a PG today very near the DCV to take a few readings. The filling rate is a measured 8LPM and when the solenoid valve closes after filling, the PG rises from its dynamic pressure of 2.2bar to 2.7bar which is only 0.4bar above its normal static pressure of 2.3bar. Using the attached formula this means that the solenoid valve is taking 1.4 secs to close, I read that a solenoid valve will normally close in 50 millisecs, 0.05secs, if so then the pressure spike should be in the order of 11.3bar? PG ~ 13/13.5bar but I'm not getting anything remotely approaching this, maybe the flexible w/machine flexible hose is taking up the spike?. You can do your own calcs, if interested.
Water Hammer
Rapidly closing or opening valves - or starting stopping pumps - may cause pressure transients in pipelines known as surge or water hammer.
www.engineeringtoolbox.com
Loose pipes more of an issue.
What's your next move @Taconite5 ??.
I'd bypass the TMV
Then move cold from ICG... Even with plastic fittings temp to see if it eradicates the problem
You say in post #12 that ......
"I added a pressure reducing valve set at 3bar were the blue star is. And a hammer arrestor on a T before the ICG. Region around the ICG is where the banging is coming from"
Is it just the one arrestor which is about 10M from the ICG?, is this where the PG is attached??. That pressure surge is quite normal IMO (and very like the one I got when filling the washing machine). The dP across the ICG (PRV) must be relatively big when you open any tap, hot or cold as its upstream pressure is only 3.0bar, You might just just adjust the upstream PRV to get it to be wide open, adjusting screw full clockwise??, that should then give you 4.5 bar static at the ICG PRV and see does it have any effect.
The 18L EV is perfectly sized and will only result in a final EV/UVC pressure of 3.7 to 3.9 bar after a full reheat to 60/65C.
"I added a pressure reducing valve set at 3bar were the blue star is. And a hammer arrestor on a T before the ICG. Region around the ICG is where the banging is coming from"
Is it just the one arrestor which is about 10M from the ICG?, is this where the PG is attached??. That pressure surge is quite normal IMO (and very like the one I got when filling the washing machine). The dP across the ICG (PRV) must be relatively big when you open any tap, hot or cold as its upstream pressure is only 3.0bar, You might just just adjust the upstream PRV to get it to be wide open, adjusting screw full clockwise??, that should then give you 4.5 bar static at the ICG PRV and see does it have any effect.
The 18L EV is perfectly sized and will only result in a final EV/UVC pressure of 3.7 to 3.9 bar after a full reheat to 60/65C.
The house had one arrestor T’d off the water meter.
I added a second one before the ICG.
That pressure gauge was on the second hammer arrestor.
I tried opening the PRV yesterday. It just made the noise louder. That’s why it’s showing slightly more than 3 bar
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
