Low pressure from un-vented cylinder - faulty PRV?

[amuiphoto]

Cheers!!!

 

[Agile]

I don't know what Tony means when he says you can't have two pressures, that is what a PRV does. It was invented for that purpose.

I mean that all hot taps fed from the unvented must be all at the same static pressure.

Something odd about an outside tap apparently giving 4 Bar.

He still does not understand dynamic pressure!

Tony

 

[Agile]

Its not possible for the same pipe system to have 1 Bar downstairs and 3 Bar upstairs or vice versa!

Who said anything about a 'same pipe' system? The downstairs tap could be straight off the mains, and upstairs (tank and subsequent shower) fed via the PRV.

Mathew

The kitchen tap should be connected directly to the mains supply. ( It makes a good point for measuring the pressure part of a dynamic flow rate measurement ).

The output of an UV cylinder can ONLY be lower! Never higher!

Tony

 

[Dan Robinson]

The output of an UV cylinder can ONLY be lower! Never higher!

Really?

 

[MJN]

The kitchen tap should be connected directly to the mains supply. ( It makes a good point for measuring the pressure part of a dynamic flow rate measurement ).

The output of an UV cylinder can ONLY be lower! Never higher!

Tony

You must be reading a different thread to the rest of us - the pressure at the cylinder and upstairs outlets was indeed (significantly) lower than the kitchen tap, that was the whole point.

Mathew

 

[amuiphoto]

Something odd about an outside tap apparently giving 4 Bar.

I can explain this - the garden tap isn't being used and is getting a build up of pressure. The static pressure (garden tap) was 4.2 bar tonight, I then measured 2.5 bar at the incoming main... took the garden tap reading again and, lo and behold, it matched at 2.5 bar.

And just for Tony, the dynamic pressure is 1.8bar!

 

[Dan Robinson]

You should also have a double check valve on the garden tap, which will, hold any increase in pressure during off peak hours.

 

[amuiphoto]

I reckon that's what's happening Dan - does that make the case for adding an accumulator and getting 4 bar all the time, capacity allowing... or have I got that one wrong?

 

[Dan Robinson]

No, you'll always be limited by the pressure regulator of the Gledhill.

If you changed to an OSO, and got an installer who knew what he was doing, then they can be uprated... Otherwise, you are stuck.

 

[amuiphoto]

B..llcks, just posted that as a new question, sorry Dan.

The Gledhill now has a brand new 3 bar PRV but I'm only putting in 2, could I get 3 out of it?

 

[Dan Robinson]

The accumulator will even out the pressure for you, but still at the Gledhill's limit of 3 bar.

I doubt it would be worth the hassle and expense.