How do I fix this leaking central heating drain point?

[nishnish]

Hi,
My central heating drain point has been dodgy for a while, but now refuses to shutoff completely. Constantly dripping.
Here it is:

It seems to be threaded into the proceeding joint. Marked

1
-
2

P

underneath.
The proceeding joint is a soldered tee, with what looks like 2x22mm pipes (maybe imperial) and at the end the drain fitting you can see.
What would I replace that with?
Do I need an imperial fitting?
Thanks in advance.[/img]

 

[cross thread]

TAKE IT APART AND REPLACE THE WASHER

 

[nishnish]

Thanks for the quick reply.
Would that be a standard washer?
Do you happen to know the type from that pic?
Is it possible to replace this with a 'better' valve?
Don't really like those square head things. I can see plenty of damage on it from previous users.
Cheers.

 

[Happyplumber]

drain the system and just replace the who drain off be alot simpler for you then looking around for washer

only couple quid to be buy

 

[HarrogateGas]

If your fairly confident and competent, then just unscrew the whole drain valve and change it for another or any other 1/2 threaded valve you choose. No need to drain, just be quick!! and put a towel underneath.

 

[nishnish]

drain the system and just replace the who drain off be alot simpler for you then looking around for washer

only couple quid to be buy

What would I replace it with? I'm not sure whether that is imperial or not.
Cheers.

 

[seco services]

it's a thread so it will be 1/2".

 

[Happyplumber]

There you go knock yourself out!

http://www.toolstation.com/shop/Plumbing/Valves/MT+Cock+Type+A+12+Screw+Shank/d20/sd2696/p18837

 

[nishnish]

There you go knock yourself out!

http://www.toolstation.com/shop/Plu...pe+A+12+Screw+Shank/d20/sd2696/p18837[/QUOTE]

Thanks to all for the very speedy replies.
Especially Happyplumber. You've knocked me out

 

[dextrous]

bit of ptfe (or loctite 55) round the thread will be required

 

[Happyplumber]

No worries,my pleasure

Fill ya boots and good luck

 

[nishnish]

It's clear now (thanks guys) that I need a 1/2" threaded fitting. After seeing Happyplumber's suggestion (which I'll get), I've also seen different types. My little knowledge is becoming dangerous.
What's the difference between:

Type A/B
Light/Heavy Pattern
Glanded

I think that latter is a gland around the square bit which stops water squirting out of it, whilst opening it? As the current design did.
But what are the others?
Cheers.

 

[TicklyT]

IMO the light pattern may have it's uses, but very rarely will it be for domestic plumbing. The difference is the lack of any glanding, meaning, as you have found, a lot (maybe most?) of what comes out the valve passes up the thread, then up your sleeve when you open it.

That may not be a problem in some industrial applications, where everything can drop straight into a sump for later disposal, but hopeless in a home , particularly one with light coloured carpets.

For the price difference, 'Ship', 'Tar', 'Halfpenny' and 'Spoil' comes to mind.

Yet some plumbers still fit the things!

 

[nishnish]

IMO the light pattern may have it's uses, but very rarely will it be for domestic plumbing

Ok. Thanks.
So glanded heavy pattern is the one to go for. As Happyplumber so sagely pointed out.
However, what's the difference between type A and B?
Cheers.