Stopcock question

Jeepers_Creepers

tony3619 said:

It looks like I have a pressure reducing valve fitted.

What exactly does this do? Keep the same flow / static pressure no matter how open the stop !!!!!! is?

Cool!

What it does is to maintain a set pressure (in this case set to 3bar?) to your domestic supply regardless of what the incoming supply pressure is like. Almost certainly your incoming mains was deemed 'too' high for comfortable use - ie it could lead shock, hammer, noisy taps and valves etc. 

This is good news as you now shouldn't have any concerns about your domestic pipework suffering problems. 

Leave your stopcock fully open. (By 'fully', I mean open it up fully, and then close it a half-turn so's it doesn't seize!) 

When you now run a tap, that system pressure should be quite well maintained, but shouldn't rise above 3 bar at any time. If you DON'T leave the stopcock fully open, then the system pressure WILL drop significantly when you open a tap since the mains stopcock will not be able to supply enough flow to keep the pressure up. 

(You can even see this happening if you look at that gauge; turn on a tap with the SC fully open, and the needle will probably flicker down to between 2 and 3 bar - that's good. Turn your SC almost off, tho', and then watch that needle hit the deck when you open a tap... That is not good - it'll be pants flow.) 

So - trust that wee valve to keep your pressure safe, and open up the stopcock 'full' in order to provide the max-flow-at-controlled-3bar-pressure you need. 

Jobbie jobbed. 

tony3619

Sorry I don't quite understand, so is it good to have a pressure reducing valve? 

grumbler

Define 'good'. Four you it's better to have it than not to have. Without it the pressure in your pipes would be too high for a domestic pipework.

tony3619

Sorry I should of been more specific. I meant will it keep the pressure at a safe level no matter how open the stopcock is? And will it control flow rate? 

tony3619

Sorry I didn't see that long explanation above! I understand now 

[Deleted User]

This is interesting:
There is no legal requirement for a maximum supply pressure. If you find that the supply pressure exceeds the maximum working pressure of internal fittings, you may want to discuss with an approved plumber about installing a pressure reducing valve.
So if something ruptures through over pressure, it doesn't appear to be anyone's responsibility. I wonder what insurance companies have to say about that.

Etcumspiritutuo

We recently had a heat pump fitted and it works fine. But during installation when we turned the water back on a large bang ensued from the sudden increase in pressure and a flexible pipe burst at one of the hand basins and ran all night without being noticed.  But now all fixed up except I have much worse flow to my showers than before with my old combi - only 7 - 10 litres per minute. I know they fixed a pressure reducer to the hot water but didn't think they touched the cold. In my kitchen sink even the cold tap only gives 12 litres per minute. Tried road and house stop !!!!!! both fully on. Gave neighbour my 10 litre bucket and it filleed in 30 seconds  so 20 litres per minute. Am at a complete loss to understand whats going on - cana stop cocks fail into a partially on mode?

Albermarle

Etcumspiritutuo said:

We recently had a heat pump fitted and it works fine. But during installation when we turned the water back on a large bang ensued from the sudden increase in pressure and a flexible pipe burst at one of the hand basins and ran all night without being noticed.  But now all fixed up except I have much worse flow to my showers than before with my old combi - only 7 - 10 litres per minute. I know they fixed a pressure reducer to the hot water but didn't think they touched the cold. In my kitchen sink even the cold tap only gives 12 litres per minute. Tried road and house stop !!!!!! both fully on. Gave neighbour my 10 litre bucket and it filleed in 30 seconds  so 20 litres per minute. Am at a complete loss to understand whats going on - cana stop cocks fail into a partially on mode?

The thread is 4 years old.
Better to start a new thread altogether with your question.