Stuck stop cock

[Kimba]

A classic I am sure, but I think it's one with a diference.

Let me paint the picture.

Ex-Council building. Huge tank on roof (no access to). Iron pipe that come down to each flat, with a stop cock on. After which a short length of iron, before the first sight of any copper.

Stopcock stuck. Tried various taping, spanners, limescale removers,WD40 etc etc. Still stuck. I can close it a tiny bit, but then I have to hold the collar with a second spaner to stop it unscrewing as I reopen it.

I need to turn it off to change some taps and a few other bits (and no service valves where put in.)

so

1. Can you freeze iron pipes? (guessing they are around 22mm size)
2. Do you need to retap a thread onto them, as I am guess they don't use compression joints?
3. Any experience with council buildings, will they turn off the supply at the tank if I can freeze the pipes, to allow me to carry out the work?
4. Could I just put a new stop cock in at the copper section, and leave the iron stuff be, or is that VERY bad practice?


Cheers people!

 

[peter anderson]

Is it your property? If not I wouldn't do it myself. If it is your property I would be interested in trying out the pipe freezing and adding a new stopcock onto the copper section idea. But I am not a qualified plumber so don't sue me please. Maybe the safest thing is to have the cistern emptied and get a plumber in who knows all about iron to change the stopcock. If the cistern is big all that water flooding your property could cause a lot of damage

 

[Kimba]

The tank supplies the entire building (around 20 flats) I don't think empting it is an option

It's my g/f flat, so an invested interst, and I think I am a fairly competent plumber, although have little experience with iron pipes (copper/plastic etc no problems).

I suspect too, the way forward is to put a new stop cock on the copper, and that I have to get the council to switch off the water for a while (hoping that each flat is INDIVIDUALLY fed from the tank), althought his might not be an option.

What worries me, is if that is a burst pipe/leaking joint etc now, we have no way of shutting off the water.. that's gotta be bad?!

 

[peter anderson]

If it is an ex-council building then why would the council get involved in turning off the water? I can't see an alternative to stopping the supply of water from the cistern to the flats by either having a possible stopcock immediately next to the tank turned off or having all of the water drained out of the tank so you can have your stopcock replaced. Maybe a pipe freezing machine on your bit of pipework could be used but personally I would get the professionals in. I live in a block of flats and we've had our supply of water cut off a couple of times so plumbers can do repairs.

 

[Kimba]

Cool, ok I shall investigate

 

[AdamW]

It is probably worth speaking to the estate managers. I assume your gf pays maintenance charges. If so, she pays them for a reason, that reason being maintenance.

I would have thought that a non-functioning stopcock counts as a maintenance job so it is definitely a good thing to see if you can get them to sort it. Then if it all goes wrong and you end up with a 20 flat cistern on the living room carpet their insurance is liable! Seeing as the stakes are high (wouldn't want to be in your shoes if it goes pear-shaped!) then it is worth pursuing the no risk approach first.

 

[ChrisR]

Something to think about: Plumber freezes pipe in a flat. but is too slow with the new valve. Ice plug shoots out of pipe and goes through a stud wall. Yes I mean THROUGH.
Then water.

Only way out if this happens is to fit a new valve wide open with water shooting through it. Do up the nut then turn the valve off, Red-Adair style. Bit of a bugger if the threads on the old nut are different, you have to remove the olive then. (assuming copper)

 

[taydo]

Oh yes Chris been there (luckily on an unused outside loo). Anglian Water didnt no how to turn the water off.

Had no room to freeze it safely. One Wet Cold Plumber at 9pm on a winters night.

4 happy cottage owners, the supply served the whole row with unmetered water to there cold tanks. Coz they all had water meters in the front gardens!