Usual pressure problem

[townfanjon]

its a popular one this , anybody know a way round it .
Mains cold , gravity hot .
Customer wants a thermostatic bath filler / shower. Several available but need to be more or less on balanced supply's.
I have thought about a prv on mains down to say 2 bar , but theres still a massive differential in pressures .
Any ideas ???? Pressure equalising valve ???
Cheers in advance .

 

[Last Plumber]

Pipe cold from CWS Tank.
That's the right way as you know doubt know.
Or did you mean you couldn't face the job and hoped and prayed that some Plumber with a massive brain had discovered an answer?

You can use a PR valve and drop the pressure right down to tank pressure but there will be a slight imbalance in certain circumstances and you'll wish you'd never done it.

In my opinion.

I can't see a Red Rose County Plumber doing it but I have no passport to your side so no experience of the goings on over the hills.

 

[Last Plumber]

I bet it's cold over there though?
Brrrhhhh!!!
I bet you're raking it in.

 

[townfanjon]

Lol , yer put the extra feed via the tank to her but quick as a flash she knew she would be bathing in tank fed water and “pulled a face “ lol .
A manufacturer ( cant remember who , too bloody old now ) did a valve / tap on something like a 6-1 differential , I fitted one out of that 6-1 and it actually worked .
As for raking it in , nah I am the quietest I have been in years , but with a full house to fettle for me and mrs TFJ its going to be a busy year .

 

[Chuck]

Any ideas ????.

Can the customer be talked into upgrading DHW to an unvented store? It's the only solution I can think of that that's going to end up working well enough for the customer to be pleased with the results.

 

[Aire]

Lol , yer put the extra feed via the tank to her but quick as a flash she knew she would be bathing in tank fed water and “pulled a face “ lol .

Is she aware she's been bathing in tank fed water for as long as she's lived in the house
Could try a venturi shower, never installed one before but the trevi boost is suitable for up to 0.3bar hot and 3 bar cold supplies.
Ideal Standard Trevi Boost Shower Valve Includes Idealrain Kit Chrome A5699AA | City Plumbing Supplies

 

[ShaunCorbs]

Bes do a balancing valve designed for mains cold low pressure hot

Water Pressure Equalising Valve - 16711 | BES.co.uk

 

[Welder]

its a popular one this , anybody know a way round it .
Mains cold , gravity hot .
Customer wants a thermostatic bath filler / shower. Several available but need to be more or less on balanced supply's.
I have thought about a prv on mains down to say 2 bar , but theres still a massive differential in pressures .
Any ideas ???? Pressure equalising valve ???
Cheers in advance .

PEV every time. HOWEVER... PEV only operate effectively if the ratio is better than 10:1
So, a 1m head of HW and a 5 bar incomer will not work. YOu really need a min of 3m of HW head and potentially a PRV on the incomer limiting the cold to 2 bar.

Also bear in mind, sad sod alert here, there must really be non return valves in both lines to the PEV because there is a hole in its diaphragm. This if course means the numbers change

If you want a PEV Jon I've one you can have.

 

[townfanjon]

Is she aware she's been bathing in tank fed water for as long as she's lived in the house
Could try a venturi shower, never installed one before but the trevi boost is suitable for up to 0.3bar hot and 3 bar cold supplies.
Ideal Standard Trevi Boost Shower Valve Includes Idealrain Kit Chrome A5699AA | City Plumbing Supplies

Yep Craig I would have considered one up to last Christmas at least , a customer had the ideal equivalent and it never worked properly, its now in my scrap bin .

 

[townfanjon]

PEV every time. HOWEVER... PEV only operate effectively if the ratio is better than 10:1
So, a 1m head of HW and a 5 bar incomer will not work. YOu really need a min of 3m of HW head and potentially a PRV on the incomer limiting the cold to 2 bar.

Also bear in mind, sad sod alert here, there must really be non return valves in both lines to the PEV because there is a hole in its diaphragm. This if course means the numbers change

If you want a PEV Jon I've one you can have.

Cheers “sweet lips” I am seeing her on Friday for another natter , but as you say its not actually going to work properly, but may be ok . I had no idea on the ratio , thanks for that .