Which flush valve for very high pressure mains toilet

[Sylvergrunge]

Hi all,
I recently replaced the flush valve on our toilet as it kept flushing (my hubby is not the practical type!!). Unfortunately the new flush valve I have installed only worked for a while and is now doing exactly the same thing. Someone mentioned to me that it could be due to the fact that our mains pressure is extremely high. I have found that if you turn the sink tap on just before the cistern is full then it lowers the pressure and the valve works and the water stops. I also tried lowering the mains pressure to the house but this had a knock on effect on the shower and makes the tap in the kitchen drip!!! So is there a flush valve I can fit that will withstand the high mains pressure we have?
Thanks in advance for any replies.

Sylvergrunge

 

[kevplumb]

torbeck View media item 674

 

[foxhole]

Flush valve normally come with a low pressure and high pressure option, have you fitted without changing the cone valve?

 

[Sylvergrunge]

I am afraid I am going to show my DIY naivety now! I replaced the unit that looks very much like the picture above. What is the cone valve?

 

[Sylvergrunge]

This is the exact one I have used:



http://www.diy.com/diy/jsp/bq/nav.j...efview=lister&ts=1258633136714&isSearch=false

 

[TicklyT]

..... I also tried lowering the mains pressure to the house but this had a knock on effect on the shower......

Partly closing the stopcock has no effect on the static water pressure, just the maximum flow rate, and may cause problems elsewhere, as you have found out. Carried to extremes, it can damage the stopcock washer and it's seat, rendering it useless when you really need it.

Conventional ball valves are usually supplied with high pressure or low pressure cones to fit in the innards. The high pressure cone has a smaller hole in the end than the low pressure one.

Torbeck valves and the like, similar to the one kevplumb posted a picture of, are usually supplied with flow restrictors that fit in the connection to the water supply pipe. They often look like a large plastic screw.

There are actually two valves in a Torbeck valve. A small pilot valve is controlled by the float allows a small dribble of water from a space behind the main valve diaphragm. When the pilot valve closes, the water pressure builds up in this space, fed through a pinhole in the diaphragm, and closes the main valve after a short delay. You may need to set the float level to close the pilot valve a few seconds before the cistern is full to account for the operating delay.

In theory, the higher the water pressure, the better a Torbek valve seals.

Grit and limescale blocking the small waterways of the pilot valve are the biggest enemies of this design.

 

[Sylvergrunge]

Thanks for all your replies. So do you think that the one I fitted did not have a high pressure flow restrictor? I dont recall seeing any other parts that came with it. Do you know if they sell Torbeck flush valves at B&Q and any advice on which one to shoose would be greatly appreciated. Dont want to go through all this again!!!

 

[kevplumb]

this might help

 

[Sylvergrunge]

Ah Kevplumb, what a useful site, thanks for that. Looks like it must have come with a restrictor which I failed to use!!! Looks like I will be popping down to B&Q for another one and making sure I put the restrictor in this time. Thanks all for your help.