changing float valve in cold water tank - and pipe freezing!

[londonboy123]

Hi-while I'm online i thought i might ask a quick question - I am going to put a BS12 part 2 float valve in my friends cold water tank-as his is leaking slightly and will only get worse. His stopcock is very stiff (even with leverage it is not able to shut off fully). I thought I'd freeze the pipe near to where the rising main enters the cold water tank, cut it, add a compression isolation valve (slotted type) then add a bit more pipe up to the water tank and install the new float valve. Is this satisfactory? I just want some re-assurance really??

The pipe freezing kit I have says it works up to 7 bar of pressure and I knw in the london area the pressure is usually 2.5 bar, 3 bar max! so this also should be fine?? I'll also have a 15mm stop end in hand in case the pipe freezing kit for some reason is faulty!!!

 

[Rico99]

Hi there,

Why not turn off external stopcock, change float valve and fit angled service valve direct to new float valve, also while mains is off change his internal stopcock to prevent any future problems.

Rico

 

[londonboy123]

Hi-i did think of that but it is water authority's property and this too may be stiff and if i snap it off or someting also, his internal stopcock is hard to get at - and getting to the pipe to cut it/add a stopcock there will be very tricky!!!

 

[Rico99]

LB,

Yes it is the water suppliers stopcock, but they can't expect you to contact them everytime you need to turn it off. Just try it and see. If there is a problem with ie stuck or buried and get them out to sort.

The internal stockcock does need changing what happens if you do have a problem when changing the float valve, you would have no way off stopping the flow, best to check external stopcock anyway.

Also, there may be somewhere else near by to fit another internal stockcock or maybe even a SureStop, this fits into the supply and turns it on/off with a switch.

Rico

 

[londonboy123]

the external stop cock needs a special key though !?

Also my mates internal stopcock key is right behind the back of the sink unit and very inaccessible.

If there is a problem and the pipe freezer fails for some reason then I will have a stop end to quickly wack onto the pipe end to stop the flow.

 

[Rico99]

LB,

What head does the external stopcock have, you can pick up tools for these from plumbers merchant for under a tenner.

I understand you have a stop end in case the pipe freeze dont work, but then what do you do when you need to get the stop end off.

Really need to make sure you can isolate the supply before you start doing anything.

Manyde soak the internal stopccock with Wd40 or 3in1 for a bit to see if you can get it to move.

Rico

 

[DCPlumbing]

Its surprising how much water can be lost whilst trying to get a stop end onto a mains pressue pipe while its running. Also the water in the pipe needs to be still for the freezing kit to work properly.

I would advise the same as those above, Get control of the water before you start work.

On the other hand, If you freeze and it does work. Before you start, Make up a speedfit No1 (streight connector) with a short length of copper in one end. To this ad a service valve to the other end of copper, You can then cut your pipe and shove on the No1 fitting giving you control in a matter of seconds should the frozen plug fail.

Best of Luck!

 

[londonboy123]

Yep i would like to turn off the supply first. BUT the prob is th stopcock is just too jammed. and it is stuck behind a worktop and cupboards/badly installed IMO. so no access to get to it to add a new stopcock! the one in the road is my only hope i guess!! are there many type of stopcock keys available?

 

[JohnD]

if you have a pipe gushing out water under pressure, it will be hard to put a stop end on it, but it is a lot easier to put an open stop valve on it. you can close the valve after you have fixed it.

 

[londonboy123]

yes true, as mentioned from a post before i will get a service pipe made up with a piece of pipe the other end in case the pipe freezing fails!

 

[JohnD]

maybe you can put a hose on the end to lead the gush away to a more convenient place?

 

[londonboy123]

be honest if a plumber was called out to change a float valve in the cw tank and had to freeze a pipe or take a while turning the water off outside, etc, they would charge a LOT more wouldn't they?!! I think I'm gonna try and get the external stopcock off before i do the pipe freeze!!! :0

 

[twgas]

if you turn off outside why freeze it as well

 

[londonboy123]

i won' if i CAN get it off outside i won't have to freeze it ! it's just getting a stopcock key that will fit the external stopcock!!!

 

[JohnD]

I've got one
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