Pipework under sink and bathroom basin with pics query

[BobbyJoe]

Hi everyone, I took pictures to better illustrate my questions and hope it helps.

The hot water pipe under the sink (top pipe) has a valve on it with the number 15 on it and the cold pipe (under top pipe) has a stopcock which stops the water coming into the kitchen sink. Does the cold pipe need a valve on it as I don't know what kind of valve the hot pipe has on it.

The basin in the bathroom has two pipes for the mixer tap, with isolation valves does it seem right, no valves required?

The cupboard outside the bathroom and above the door has two pipes coming into the flat, main cold water feed pipe with a 22 mm NRV on it which has the red gate valve which is fully opened, does it need to be positioned fully open?

The hot water pipe next to the main cold water feed pipe has no NRV does it need one or is it fine the way it is.

Any information as always would be appreciated, thank you.

 

[steadyon]

1. Hot pipe above cold stopcock has a 15 mm isolation valve on it. Cold doesn't need anything provided stopcock is OK.
2. Basin - no additional valves beyond the two isolation valves required. Those flexihoses should not have been screwed directly onto the isolation valves, but if they haven't given problems, leave well alone.
3. Gate valve should be fully open.
4. Hot water pipe doesn't need a non return valve.

All the isolation valves fitted are restricted bore valves. If you have problems with flow rates, changing them to full bore versions might help.

 

[BobbyJoe]

Gate valve should be fully open. I checked it as the last plumber turned it a quarter to stop it from ceasing the same for the stopcock under the sink.

Those flexi hoses should not have been screwed directly onto the isolation valves. How should they be fitted if not onto the isolation valves?

Is the purpose of restricted bore valves and full bore valves to do with water flow rates or other?

Many thanks

 

[steadyon]

1. The plumber is quite right. Always open gate valves and stop cocks fully (unless having a good reason not to) and then close back 1/4 to 1/2 turn. Helps to stop them seizing up.
2. They make a seal between a flat edge on the valve, and a rubber washer inside the end of the flexi. Valves designed for compression fittings have a 45 degree bevel on the inside diameter, with a relatively sharp edge. This sharp edge can cut into and spoil the rubber washer. Correct ways to do it are:
2a. Use an isolation valve with a flat edge. You can buy them, but not sure whether you can get full bore ones.
2b. File the sharp edge of an ordinary isolation valve. Not that difficult, but you need to keep the end square to the body.
2c. Get an adaptor, such as Screwfix 2665R. Plain shank goes into isolator valve for normal compression, threaded end has a flat face to affix flexi.
2d. Get a 1/2" to 15 mm compression male iron (they are made of brass) and a short length of 15 mm pipe. Pipe into isolation valve compression, compression end of iron onto other end of tube, flexi onto 1/2" end of iron.
3. Flow rates.

 

[Bobbyjo]

Thank so you very much.

Use an isolation valve with a flat edge, is it similar to the following link and are the current isolation valves removed and these replace them?

Chrome 15mm x 1/2 Flat Faced Isolation Valve - 07000001

Chrome 15mm x 1/2 Flat Faced Isolation Valve Isolation valve to connect on to 15mm pipe with a 1/2" BSP flat faced thread on the other side to

www.plumbers-mate-sales.co.uk

 

[BobbyJoe]

Are one of these okay to buy and which one would be best for my basin pipe works thanks.

BES.co.uk | Next Day Delivery On 15,000 + Plumbing Supplies

Order isolation valves and other brassware online at BES.co.uk. Low Prices, Free Next Day Delivery Available, 15k Plus Products in stock. P/N: 23573

www.bes.co.uk

Chrome 15mm x 1/2 Flat Faced Isolation Valve - 07000001

Chrome 15mm x 1/2 Flat Faced Isolation Valve Isolation valve to connect on to 15mm pipe with a 1/2" BSP flat faced thread on the other side to

www.plumbers-mate-sales.co.uk

https://www.NoLinkingToThis/p/compr...Vh57tCh1tAANvEAQYASABEgLeePD_BwE&gclsrc=aw.ds

 

[clonkel]

Those flexihoses should not have been screwed directly onto the isolation valves

Is there are reason for this. I am a DIY plumber and have always used flat isolation valves with the tails directly fixed into them.

thanks