Flow rate of bath taps

[sven2020]

Hello to all and a happy new year!

I have a bath with two quarter turn taps which have a flow rate of approximately 24 litres per minute on each tap as i have an un-vented system.

The taps are being replaced as the chrome has blistered to hell.

I have ordered a pair of Bristan quest quarter turn bath taps from screwfix (item 22970) that are suitable for high or low pressure systems.

NOW! On the spec sheet it states that the flow rate for these new taps is -

Flow Rate (Ltr/Min) 11.50 Ltr/min (exact wording from spec sheet).

My question is...........What will be the flow rate of the new taps???? They dont have a PRV built in, so why should the flow rate be so low when compared to the old ones? My water pressure hasn't been reduced. I'm not using flexi hoses or iso valves. The taps have a 22mm tail same as the old ones. (22m coupler to 15mm pipe).

Am i misreading or misunderstanding the Flow Rate info listed above? Surely the same design high pressure taps should give the same flow rate as this is dictated by my unvented water system?

Does Ltr/min mean - Litres per minute or minimum? Also - a lot of different spec sheets do not list the flow rates, or even the size of the tails! Some say 22mm, some say 3/4 inch and some say none of the above??? I just want to know if these new taps will give the same flow rate as my old ones.

So confused!! Thanks in advance for any explanation.

 

[ianmcd]

11.50 L/min is the minimum flow rate they will be fine

 

[Newboy]

I suspect that you're a victim of the Screwfix random specification data!

Bristan gives flow rates based on the system pressure - min. pressure 0.2 bar / max pressure 8.0 bar

System Pressure (bar) - Flow rate (Ltr/minute)
0.2 - 11.5
0.5 - 19.3
1 - 27.2
2 - 38.5
3 - 47.2
5 - 60.9


The tails are 3/4" (not 22mm)

 

[sven2020]

11.50 L/min is the minimum flow rate they will be fine

AAAAAARRRGGH!! Brilliant, that explains that, thankyou so very much, shame they didn't make it a bit clearer for a dunce like me.

Cheers buddy!

 

[sven2020]

I suspect that you're a victim of the Screwfix random specification data!

Bristan gives flow rates based on the system pressure - min. pressure 0.2 bar / max pressure 8.0 bar

System Pressure (bar) - Flow rate (Ltr/minute)
0.2 - 11.5
0.5 - 19.3
1 - 27.2
2 - 38.5
3 - 47.2
5 - 60.9


The tails are 3/4" (not 22mm)

You're right i have been a victim!! Thanks so much for the info that's really helpful, handy to have to!
One question though - 3/4" and 22mm are surely different sizes, so why do their spec sheets say 22mm on some and 3/4" on others? Or is this just screw-you-fix's way of confusing people? I mean, i looked at taps that said 3/4" tails and didn't order them thinking they would be too big. I assume then that they are refering to the OD of the pipe taking into account the pipe thread? if that's the case then i see what you mean about random spec data.

Thanks again for your input.

 

[ianmcd]

i looked at taps that said 3/4" tails and didn't order them thinking they would be too big

The taps will indeed be 3/4 BSP threads hence why you need either a pap adapter or flexi pipe which is 3/4 Female BSP at one end and 22mm compression at the other