Stopcock - Identifying black pipe dimensions to replace stopcock

[Steve Newton]

I have a non-standard stopcock that needs replacing but I can't identify the size....

There is a smooth flexible black pipe coming from the mains but this is 21.35mm in outer diameter. It has compression fittings on that end, and on the 15mm end.

The current stopcock has a BS logo, 88 and 1/2 on it. It can't be a half inch fitting though so I don't know what this relates to....

I assume the black pipe is non-standard now but need a new stopcock to be able to fit...

Any ideas gratefully received!!

Cheers

Steve

 

[JCplumb]

I'd try to service it rather than replace it TBH.

 

[Steve Newton]

I'd try to service it rather than replace it TBH.

I had considered that as an option but, having never stripped a tap before, haven't got a clue on what components I would need or how to go about it.

Do you know of a step by step guide online?

 

[wiggers]

I also would leave it why dont you just put a new stoptap above existing one, what is the black pipe made from?

 

[Steve Newton]

The stopcock is leaking from the spindle so needs replacing or repairing....

I believe, from research online, the black pipe is "half inch LDPE".

It has an outside diameter of 21.3mm, I believe the "half inch" relates to the internal bore size??

I'm struggling to find much information tbh - I'd prefer a replacement stopcock if possible.....

 

[wiggers]

If it is plastic it could be poly-ork or hunter genova getting spares is difficult

 

[PlumbBobBob]

wouldn't a 3/4 olive in 22mm / 15mm stopcock work?

 

[snowhead]

Plasson universal connector 77010252. 25mm x 20-27mm
Then a Plasson 25mm to 15mm C.u adapter 7438 to fit in the above
Then a standard 15mm stop tap above that directly onto the old 1/2" copper pipe.

 

[Plamber]

I take you have tried tightening the packing gland?

 

[tamz]

wouldn't a 3/4 olive in 22mm / 15mm stopcock work?

Of course it would but so would repacking the valve

 

[BLOD]

If Its not possible to service the stop tap it will need replacing.
I'd use a philmac compression fitting to go from black plastic to,15 mm copper, about £10 from plumb centre
Youll need to cut the black pipe about 2 inches below the stop tap to miss the copper stiffner.

 

[Carl86]

But before you do any of that make sure the water is switched off, from the out side. Otherwise use ya flippers and snorkel and try and go for a gold medal jumping that sucka live(not recomended so i wouldn't try lol its poor advice).

 

[JCplumb]

Give it a good clean up and repack the gland. Dead easy 2 minute fix, don't even need to turn your water off.
Search on here, Youtube or Google and you'll get guides on repacking glands.

 

[Carl86]

If its weeping round the spindle, i genraly give the nut a nip. If that doesnt work I losen the packing gland and use a bit of loctite 55, reseal. Id clean up the stopcock like previously said, if needed a bit of WD40 and a good wipe down then loosen. Have a dish and an old rag handy to catch any dribbling water.

Like JCplumb said have a look on google, there will be variations on whats used to repack the gland on the guides shown.

 

[Best]

If a 3/4" olive fits tight on pipe, then a 22mm-15mm stopcock will do as all that matters is you use the original copper support liner. But why change it??
If you did go to the bother & expenses of changing that stopcock, you will probably find the new one poor quality & don't be surprised if it leaked immediately from the packing nut!
Nothing wrong with that stopcock by the looks of it & if it is good inside, then just put a new washer in it if needed (there is nothing complicated about these) & clean the spindle, screw the packing nut back, clean packing nut threads with a knife blade, then drop of Vaseline & retighten packing & usually no need for repacking, although an option. Back to new. All just a 10min job. Normally just need to fix the packing nut only, so no need to shut water off then.
You could fit a 15mm lever valve above it for a handy shut off.

 

[leepoll]

I think the black pipe is black alkathene, we see it a lot on the farms we work on.

 

[glenno1]

I agree with black alkathene,but i would re-pack the gland.Turn off tap undo the small nut, put couple of rounds of ptfe on round the spindle.push nut back in place,tighten up,turn on ,job done

 

[jtsplumbing]

Black Alkathene (LD) low density ! if stopcock is a bit ropey get a new stopcock or outside tap and swap over head unit (Turn off water from outside first)

 

[WaterTight]

Didn't I read on here that that black pipe becomes really brittle when old? If so be dayum careful my man.

 

[kozak1968]

Alkathene comes in various sizes. You can get adaptors to fit various materials. Some plumbers merchants will let you have the various sizes then just return the ones you dont use. It depends how well you get on with the merchant.

 

[dsteves619]

Make sure you support the stopcock/pipework if you are taking the body out to service.

 

[WHPES]

Black alkathene pipe only really becomes brittle with age if it's exposed to sunlight (i.e. UV degradation). This is why blue pipe should never be used above ground where it's exposed to daylight. Modern MDPE black pipe has UV stabilisers in it.

 

[jackplumb]

Looks like Alkathene pipe to me, plumbers merchants do an adaptor from this to standard sizes. Don't forget the inserts though. If you can take a sample and they'll give you the correct fitting.