new taps fitted hot water pressure dropped ? All aspects of plumbing questions and answers, help, tips and information

[dogsella]

hi i have just fitted a new kitchen sink mono tap mixer with flexi tails and they have 1/4 turn ceramic valves in them. also the new bathroom basin taps are also ceramic 1/4 turn but not a monobloc design. since replacing my old taps (not ceramic 1/4 turn) the hot water pressure is crap??? i am puzzled on this one..can anybody give me a bit of info on why they are like this..cheers (i have a normal (older type water system with a hot water tank in the bedron cupboard. not a combi boiler

[simpleton]

Are the taps designed for low pressure systems? Whats the minimum working pressure? On gravity systems I find its always best to stick with conventional taps

[Kenj]

The monoblock taps will have either a 10mm or 12mm tap connection.
Older style sink taps will connect directly to a 15mm diameter pipe.
Assuming a 10mm pipe then this can take only 50% of the volume of water that the 15mm pipe could take.
Try the maths is you don't believe me - Surface area = pi x r x r.
So you should expect to get lower pressure, especially with a gravity fed hot water system.