connect a new supply pipe to this old one

[JohnD]

I have dug a hundred years of mud and gravel out of the consumers' stop-cock pit. Inside I find it looks like it is on half-inch copper stubs wiped into lead pipe of same internal size.

I* am going to replace the pipe to the house with a new plastic one, due to a leak. The adjacent water meter in the pavement has a T-handle to turn off the supply (though at the moment Thames Water have taken it off due to the leak)

1) What should I use to connect to the old copper stub? The old stopcock is (probably) a hundred years old, will a modern fitting go straight onto the old nut, and will it be a compression joint with an olive?

2) Should I take off the old stopcock or leave it in place? It is very stiff but is not weeping. Do I actually need a stopcock in that pit at all or can I just connect plastic pipe to the stub?

3) since the old pipe from meter to stub is half inch, will I gain better flow by using 25mm plastic, or may I just as well use 20mm? (I happen to own a coil of 20mm already)

My instincts are to do a first class job, but this house is being sold shortly so I don't want to give myself additional effort and expense without benefit to me. The brick pit is 23" from rim to floor, and about 24" x 18" with an iron lid. The run to the house is about 10 metres where it turns up and goes to the kitchen sink and loft tanks, I can put a stopcock here if I is worth it.

the pit

View media item 23857
this shows where the adjacent meter is

View media item 23858

* I am going to get the pipes, connectors and valves for the job

 

[kirkgas]

The stub will be brass, not sure what will go on it to be honest.

You might need to file it down to take a 15mm coupling, forget using a new nut onto the stopcock, i dont think you will get anything that size

 

[JohnD]

it was not the stopcock I wanted to re-use, but the nut. I was assuming that it would be captive on the stub. Do you know if it will be a compression fitting with an olive, or something else? I remember steel water pipes used to have a flared end so the fitting could not come apart if it froze.

 

[TicklyT]

Imperial BSP threads are still in common use, even on 'Metric' accessories.

Will the stop tap accept a 1/2" or 3/4" BSP tap commector?

 

[stardanny]

Hi.

Can't you dig closer to water meter? If the water meter is plastic, chance that there might be a short bit of blue polypipe between the outflow of meter to lead pipe with leadgrip ( can't remember the name ).
Might be easier to connect to blue poly pipe from there?

Dan

 

[compheat]

The brass section will be a nut and liner, the liner will fit into 22mm copper and can be soldered on. then you can change to MDPE

 

[JohnD]

@ TicklyT, yes, I know BSP threads are still used. I just don't know yet how this one works

@ stardanny, yes, that is the way I would consider best, but there is nearly a metre of digging, mostly under the pavement or a concrete sill, and to make a new connection to the meter I would presumably have to pay Thames Water some hundreds of pounds, which, as the house is to be sold soon, would not be good value for me

@ compheat, thanks, that is very useful. I take it that if we cut through the downstream lead pipe, and undo the nut, we will be able to put our new pipe downstream of the old stopcock by soldering a connector to the stub on the bench. But how would we go about connecting upstream of the old stopcock, if we want to put a new larger stopcock on, or larger pipe? I am not keen on trying to solder onto a stub in old lead pipe that will still be a bit wet and is at the bottom edge of a pit. Both the old-timers I used to know who could do wiped joints are beyond helping me now

 

[picasso]

use a philmac universal coupling straight on to the lead, have a look here.
http://www.philmac.co.uk/

 

[Agile]

That valve has a union ( taper connector ) and are still made by Talbot who were bought by Thames Water but rarely available independently. Possibly the company were sold on since.

The spligots are 1/2" and would fit a 15mm compression as they are virtually the same size.

But the solution would be to use a LeadLock™ on the lead part.

Tony

 

[stardanny]

What about using 3/4 or 1/2 inch male taper or BSP x 20mm MPDE?

Remove old stopcock, screw connector onto nut, like a tap connector to a tap.

Or use Leadlock, as Agile say.

Sometime I have a bit of every fitting and try it till it work.
Dan.

 

[Agile]

What about using 3/4 or 1/2 inch male taper or BSP x 20mm MPDE?

Dan.

Exactly which connector did you have in mind?

I have never found any connector which fitted.

In any case the stopcocks are 100 years old in many cases and overdue for replacement.

Tony

 

[MIGEM]

I dont think I would trust the lead to stay intact after swinging off a spanner. This might help you.
http://www.philmac.co.uk/wp-content/uploads/Utc_3G_tech_manual_METRIC-IMPERIAL_email_version.pdf

 

[stardanny]

Exactly which connector did you have in mind?

Well, I work with Housing Ass. and we have many of 1940's houses stock with lead incoming main.
We replaced old lead rising main / DHW iron pipes and the incoming lead and stopcock get replaced at a later stage. When we connect to stopcock, we find by using conex 3/4in tap ext ( if inside dia of stopcock outlet is too small for tap connector to fit in ) and 3/4in x 22mm tap connector with fibre washer will fit over stopcock outlet thread.

Maybe try remove old stopcock and use 3/4in or 1/2in male BSP to 20mm MPDE. Polypipe do make that, I think, I will find out.

I have never found any connector which fitted.

Like i say, try all it till it fit and work. It never stop me.

In any case the stopcocks are 100 years old in many cases and overdue for replacement.

True, i've yet to come across a 100 years old stopcock. If i was me I would remove it and run new MPDE straight to existing MPDE coming from water meter with straigth coupler. To OP you can do this with out touching water meter.

 

[JohnD]

...The spligots are 1/2" and would fit a 15mm compression as they are virtually the same size...

this looks to me like the easiest solution that does not involve trying to find some special part.

Any downsides to this? I gather than the end of the spigot that goes to the tap will be belled out so would have to be cut off to replace the old stopcock. But of course we will try removing the old stopcock so we can see what we're dealing with, first

And are we agreed that the spigot will be brass not copper? Will an ordinary "wheel" cutter work on it?

(I can't reach the meter, or any MDPE coming off it, without digging up the pavement. The meter is down a 200mm-ish hole that's at least 600mm deep. I have explained above why I agree this would be the best solution but don't want to do it)

 

[Nige F]

Is he Mr. Quatermass I`d see if I`m A Martian can give an answer