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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> High pressure taps v's low pressure taps https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1272990730 Message started by PatPending on May 4^th, 2010, 5:32pm

Title: High pressure taps v's low pressure taps
Post by PatPending on May 4^th, 2010, 5:32pm

I have seen some taps listed as 'high pressure'. I have a low pressure gravity system.

Can these taps be used on a low pressure system or does some aspect of their design preclude their use?

Or do they have something special that is required specifically for high pressure systems but would not prevent low pressure system use?

Also, as I have a pump serving one shower does this one shower require a high pressure tap?

Kind of ambiguous, I know but thought it worth checking.

thx

Pat

Title: Re: High pressure taps v's low pressure taps
Post by thescruff on May 5^th, 2010, 12:20am

You may get a dribble from the taps if you use high pressure type.;

If the shower is pumped then it's classed as high pressure.

Title: Re: High pressure taps v's low pressure taps
Post by londonman on May 7^th, 2010, 11:16am

'Dribble' may be a tad OTT but also could be a dribble. Depends how high up your tank is relative to your taps. We have a low gravity feed (ie tank in the loft) but because most decent stylish taps are low-pressure have gone for those. The flow downstairs in the kitchen is OK-ish. It doesn't gush and splash all over the place. But having said that I have a couple going into the upstairs bathroom and as I have a shower pump going in as well I may well use it to feed the water to the taps as I suspect that the flow will be too low.

Title: Re: High pressure taps v's low pressure taps
Post by CWatters on May 7^th, 2010, 4:43pm

Probably the worse taps to choose for a low pressure gravity system are quarter turn ceramic cartridge mixer taps that are designed for a single hole in the basin. To get the pipes through that hole flexible hoses are normally used and the internal bore can be very small. Have a look at examples in the DIY stores. Also take a look at the hole in a ceramic cartridge, even fully open less than half the area is available...

The best type are probably the old fashioned victorian bulbous taps that use a traditional washer. The bulbous shape was designed to allow plenty of area for the water to flow through when the washer is lifted off it's seat. They were that shape for practical reasons.

For a a low pressure gravity system choose taps that say they only need 0.1-0.2 bar (= 1-2 meters of head). If they are modern quarter turn ceramic types check you can take them back if they don't perform as expected.

Aside: Actually it's a bit meaningless to say a tap needs 0.1 or 0.2 bar. That's like saying a light bulb needs 240 Volts when you also need to know how bright it is to compare it with other bulbs properly. Ideally the specification for a tap should say something like "This tap will deliver XYZ Liters of water per min when connected to a 0.2 bar source".

Title: Re: High pressure taps v's low pressure taps
Post by londonman on May 11^th, 2010, 6:07pm

CWatters wrote on May 7^th, 2010, 4:43pm:

.......
Aside: Actually it's a bit meaningless to say a tap needs 0.1 or 0.2 bar. That's like saying a light bulb needs 240 Volts when you also need to know how bright it is to compare it with other bulbs properly. Ideally the specification for a tap should say something like "This tap will deliver XYZ Liters of water per min when connected to a 0.2 bar source".

Now that is one of the most brilliant ideas - take a Karma.