Close Coupled 22mm Feed and 22mm Vent Separate ok?

[wildhorses]

Hi just rejigging some pipeway after a HWC move and the old 15mm feed was pretty blocked so have replaced with a 22m feed into the main flow.

So I have flow coming from the boiler coming up to room then to a 22mm vent T then a 22mm feed T both practically touching so well within 150mm and the the pump and the the three port valve. Will this be ok does the 22mm feed cause any extra pressure in comparison to the old 15mm feed or if it does can I just turn down the isolation valve a bit to limit the fill?

thanks

 

[tamz]

It will be fine

 

[Sid Viscous]

Upsizing pipe work will never increase pressure, only increasing height of f&e cistern will increase pressure. Throttling isolation valves will not reduce pressure either, only reduce flow

 

[Mike Jackson]

The worrying bit is the mention of an isolating valve. There should be no valves on the cold feed or open vent.

 

[wildhorses]

ok thanks, the F&E tank is on the same platform as the cold tank (so in effect the F&E) is lower then the level of the water in the cold water storage as it was before, so that should all be ok thanks

 

[tamz]

It makes no difference where the F&E tank is in relation to the storage tank.
Just don't tee the overflows.

 

[wildhorses]

The worrying bit is the mention of an isolating valve. There should be no valves on the cold feed or open vent.

the isolator on the feed is there for servicing and so it can be mains flushed without the use of bungs so no probs but thanks for pointing it out

 

[wildhorses]

It makes no difference where the F&E tank is in relation to the storage tank.
Just don't tee the overflows.

each over flow is piped as a separate run out of the end of the roof, I was told many years ago that the F&E tank water level should be lower if possible than the storage tank ideally. Anyway no problems thanks for you help

 

[Mike Jackson]

the isolator on the feed is there for servicing and so it can be mains flushed without the use of bungs so no probs but thanks for pointing it out

But it is a problem, it shouldn't be there. The cold feed and open vent are safety features, equivalent to the PRV and expansion vessel on a sealed system and there should be no valves between the boiler and the F&E tank. It may make life easier but you have potentially compromised the safe working of the system.

 

[stevetheplumber]

lots of comercial boiler house have a valve on the cold feed in theory you only need the vent as a safety good practice might be to put a lockshield on