too much pressure??

[jony p]

hi guys,

please could someone give me some advice on what it could be and why my basin tap (cold) is literally full blast as soon as i open the tap even slightly?? and it obviously splashes out of the basin onto the floor

Thankyou

 

[migoplumber]

sounds like you have high pressure mains to your house, the other taps in the house should be the same tho. it could be the type of tap if it is just affectiing your basin tap, in which case you could adjust the flow (not the same as adjusting pressure) by turning down the isolating valve you have fitted (hopefully) underneath the basin.

if the pressure is too high throughout the building, and is causing you a nuisance, then you might wish to install a pressure reduction valve on the incoming main.

good luck
shaun

 

[Plumbstar Tom]

Yep, sounds like too much pressure, I'd look to whack a PRV on the mains and pop it to about 3 bar. Do you know what your incoming pressure is

 

[jony p]

excellent,

thankyou for your replies!! very helpfull. not sure on incoming pressure yet but will check it out!

it is doing it on my bath tap too but obviously not splashing over the edge

thankyou for your help and i will look into the prv!

 

[Alanka]

Another possibility is that the basin tap is faulty. Sometimes a damaged washer (if it is a washer type) sticks in the seating as you open the tap, then suddenly pops off allowing unexpected full bore flow.

If so, servicing the tap (new washer, reseat, lubricate the mechanism) will cure this.

Just a thought, before you get busy with pressure-reducing measures.

 

[Plumbstar Tom]

Another possibility is that the basin tap is faulty. Sometimes a damaged washer (if it is a washer type) sticks in the seating as you open the tap, then suddenly pops off allowing unexpected full bore flow.

If so, servicing the tap (new washer, reseat, lubricate the mechanism) will cure this.

Just a thought, before you get busy with pressure-reducing measures.

Hi Al

That wouldn't lead the tap to flow over the basin though would it?

 

[Plouasne]

Hi Al

That wouldn't lead the tap to flow over the basin though would it?

If it is a sticking "jumper", it can be "cured" by taking the jumper stem and giving it a tap with a hammer to "spread" the top end of the jumper, (not too much, or you will not be able to get it back in the hole in the spindle) then lightly tapping the jumper back into the hole

If the jumper has a groove cut into the spindle close by the washer plate, and the threaded spindle has a slightly raised "V" shaped inner edge to it (what was known as a "bumped" captive jumper), put the jumper back into the hole and lightly tap the jumper to encourage the raised edge to curl over into the groove in the jumper spindle

 

[MidJeff]

hi mate i have come across this a few times normally if there is an isolation valve on supply i usually slightly close valve.

 

[Alanka]

The original problem was that the flow came on full blast suddenly. If it were just a very high pressure supply, steadily opening the tap a little bit would not normally result in full flow suddenly - the flow would gradually increase as you opened the tap. That's why I suggested the tap might be faulty.

Of course, if the pressure is very high, this can result in the basin overflowing when the tap is opened fully. Some curved shapes of basin do shoot the water over the front edge even with moderate flow, if the jet from the tap hits the 'right' part of the basin, causing the water stream to curve round the basin and go over the edge (into your lap)!

 

[bobpape]

If it has just started to happen,
Is the cold supply on the main
how many floors does the house have.
have the waterboard been digging in your locality,

Whatever the fact that two taps are involved suggest to me it is air somehow getting
into the system,

 

[Plumbstar Tom]

It may be Ceramic disc taps opening quicker than standard turn taps???

If it's doing it on the Bath as well it all points to high pressure...needing a PRV

 

[jony p]

hi guys,
thanks for all your help and suggestions maybe i explained it wrong but the flow of water is not a "Graduate" flow, it comes out very fast as soon as i slightly open it.

i have just bought the house and found out yesterday it is a direct system and no prv fitted.

when i turn the service valve shut slightly it does help (just like turning the main stopcock down slightly) but i am not sure weather this would be a good thing because they are just meant for a temporary thing and you never know when i might need it

 

[Plumbstar Tom]

I would pop a PRV on straight way, put it at around 3 bar which will give you plenty of pressure and not splash out the basin. £30 - 45. sorted

 

[Alanka]

I would measure the pressure (or get it measured) before even considering fitting a pressure-reducing valve.

If partially closing the servicing valve to the tap works, then do it! No harm will result and it will solve your problem immediately. You will still be able to shut off the valve fully when you want to service the tap.

 

[Plouasne]

A pressure reducing valve does what it says, reduces the pressure in the pipe work after the valve, throttling down a stop valve only reduces the running pressure, not the static pressure

 

[Alanka]

This is very true. But the problem only arises when the tap is opened - that is, when water is running. There is (apparently) no problem with the static pressure, is there?

So reducing the flow when the tap is opened (by partially closing the servicing valve to reduce the running pressure) would seem to do the job.

After all, that's how you regulate flow when using a tap - you partially close or open its built-in valve to get the desired flow rate!

 

[Beeline]

Ceramic tap washers - they open fully in a qtr turn so it's nigh imposible to open slowly. You can change them for traditional type if their not a mixer tap sometimes.
Cranking the isolaters down can help the problem, but also create a lot of noise.
A PRV does 90% of a remedy but can still allow higher pressure upon first opening tap until it settles again.(1 second ish so MUCH better)
Sometimes changing the diffuser at the tap end can "spread" the flow giving less of a jet to splash back - as it were.

 

[D34no]

The only problem with throttling the isolation valve is that it can start screaming! Check pressure fit prv if needed

 

[Plucky]

Was going to say about the noise. No one wants to live in a house where each tap screams its nuts of when you open it.

£40 Pressure reducing valve. Job done properly.