PRV with Gauge Question

[techweb]

Hi,

I have a Caffeli PRV near the mains stopcock. Static pressure fluctuates between 3-4 Bar and when a tap is opened it sits around 2 Bar. No issues with pressure but trying to gain an understanding of how it should be setup to protect appliances. I do have a couple of Grohe toilets that make a slight thump when the filler shuts off abruptly.

With taps running is I adjust the PRV I can decrease / increase the pressure but it tails off (doesn't increase) beyond 2 Bar. Is that where I should set it at? From what I have read, the fact that my PRV adjusts pressure with water flowing indicates that I can't control the static pressure. Is static pressure of 3-4 Bar too high?

Thanks in advance...

 

[John.g]

Presume you have a PG installed like the one below, if you set that to slightly above 2.0bar, say 2.3bar, with a tap running, then does it rise to 3 or 4 bar immediately you shut the tap? or does it creep up?, when you do set it up to 2.3bar, flush the toilet and see does the thump co incide with the pressure rising fast to 3 to 4bar.

 

[techweb]

Presume you have a PG installed like the one below, if you set that to slightly above 2.0bar, say 2.3bar, with a tap running, then does it rise to 3 or 4 bar immediately you shut the tap? or does it creep up?, when you do set it up to 2.3bar, flush the toilet and see does the thump co incide with the pressure rising fast to 3 to 4bar.

View attachment 95000

Yes similar to that. Yes as soon as tap closes, pressure goes to wherever it was before.

 

[John.g]

What model Caleffi is it?. Some are "drop tight" which means they will maintain the set point pressure when the demand ceases, while this rapid rise in pressure may not be the problem, it probably would be better if it didn't occur.

 

[techweb]

What model Caleffi is it?. Some are "drop tight" which means they will maintain the set point pressure when the demand ceases, while this rapid rise in pressure may not be the problem, it probably would be better if it didn't occur.

To be honest, I don't know. I could grab a picture but not sure where the model number is. I imagine this one manages the flow when there is demand as when I turn it down, it with a tap running it reduces the pressure.

 

[techweb]

Photos of PRV if it helps with identification.

 

[ShaunCorbs]

The brass Stop tap is the wrong way round

Sounds like it’s operating like it should

Set pressure 2 bar 4 bar static

 

[techweb]

The brass Stop tap is the wrong way round

Sounds like it’s operating like it should

Set pressure 2 bar 4 bar static

The lever valve is as it comes in, then through the PRV and then the brass stop tap before going into the house. That's correct isn't it?

I was more interested in whether there was a way to reduce the static pressure, 4 bar seems a little high.

 

[ShaunCorbs]

The lever valve is as it comes in, then through the PRV and then the brass stop tap before going into the house. That's correct isn't it?

I was more interested in whether there was a way to reduce the static pressure, 4 bar seems a little high.

Correct if you look at the brass stop tap eg top on flow will be to the left when it should be going to the right

 

[techweb]

Looking at this i'd say it was correct... As in water flows in the way it should do.

 

[John.g]

The flow is upwards through the PRV, it looks like the PG is on the inlet side, but that would be unusual as i thought there is normally only a PG tapping point on the outlet side.