Torbeck valve in an F&E tank

[RF Lighting]

I have fitted a torbeck valve into a CH F&E tank as the old ball cock type valve had stuck closed, and being all plastic it looked like less can go wrong.


However the tank has been overflowing for a few days, so I popped up in the loft and found the bubble of trapped air in the float which operates the valve arm had escaped so the valve was not shutting properly.

Are these valves actually any good, or should I put back a traditional style?

I took a video of the valve still open while the tank is overflowing, but it isn't too clear.




Thanks for looking

 

[Gasguru]

Take out the Torbeck since you won't be able to set the correct water level and fit a Part 2 brass valve.

This will have an adjustable float. Set the valve so the water level in the tank is approximately 50mm above the cold outlet with the heating system COLD. You may also need to gently bend down the float arm to achieve the required water level.


A Part 1 valve may be fitted provided a check valve is also installed to prevent backflow. since there is less to sieze in a Part 1 valve they may prove slighly less prone to sticking in the future.

 

[JohnD]

OOI, was the float punctured? I like Torbecks but they only have a couple of inches travel, so would be difficult to set for the very shallow (cold) water level that you need, to give room for expansion when hot.

I'm sure some clever person could tell me how much volume 100 litres of water expands by when hot.

 

[TicklyT]

I'm sure some clever person could tell me how much volume 100 litres of water expands by when hot.

The expansion of water isn't linear, but i think it will be something like 2 litres for a 100 litre system raised from 10 degrees to 60 degrees C.
Of course, the volume of the system will also change as the materials (copper pipe, steel radiators etc.) expand as it warms up, so things start getting very complicated very quickly!

 

[ChrisR]

Yes it is only a couple of litres. (Water expands by about 4% between 4º and 100º)
We all get very concerned about the need for the space for the water to expand without overflowing, but extensive computation shows that the height it rises, in a normal header tank, is about the same as the thickness of ma wee pinkie. Not really enough to bother about!

"Big" domestic systems, with say 20 rads, often have TWO header tanks. Complete waste of time - and space.

 

[RF Lighting]

Thanks for that guys.

OOI was the valve I got faulty as the 'float' bit has an open bottom and seems to rely on trapping a bubble of air, or is this normal for these valves?

Off to buy a nice shiny part 2 valve now....

 

[JohnD]

the float should be a sealed "can" in translucent whitish plastic. It should have a top half and a bottom half sealed together.

 

[Gasguru]

Er what about the latest Torbecks then

http://www.opella.co.uk/PDF Lefleats/Torbeck BE LF00115 Leaflet.pdf

Accessible filter and restrictor a nice feature - they just need an adjustable tail to be the dogs....

 

[JohnD]

So I was wrong about the latest float

 

[RF Lighting]

Thats the fellar.

All the air escaped from the float after maybe 8 weeks, causing the tank to overflow

I'm no plumer, but it doesn't seem very good to me

 

[corgiman]

bad idea to use a torbec in a CWS

as has been said, stop being lazy and change it for a part 2

 

[ChrisR]

All the air escaped from the float after maybe 8 weeks, causing the tank to overflow

Some of it at least would dissolve in the water...

Torbeck = leak split break stick bang junk

 

[Softus]

Torbeck = leak split break stick bang junk

I didn't know you spoke Danish Chris!