Author Topic: Tapping off a pipe.  (Read 724 times)

quixoticgeek

  • Mostly Harmless
Tapping off a pipe.
« on: May 09, 2020, 04:57:32 pm »

I have a cold feed that currently goes to the shower, I'd like to fit a T piece to it, and run a short spur of pipe to a tap that I can then connect the washing machine to.

The pipe I want to connect to has an OD of 12.7mm. Can anyone suggest what type of pipe I fitting I should be looking for? 12.7mm == ½". But I thought ½" pipe had an OD of 15mm, not 12.7mm.

I'm guessing the tool of choice is going to be a dremel with a cut off disk.

Does anyone have any advice on such a procedure?

J

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Beer, bikes, and backpacking
http://b.42q.eu/

Re: Tapping off a pipe.
« Reply #1 on: May 09, 2020, 05:00:02 pm »
Does anyone have any advice on such a procedure?

Yes, turn off the water at the mains before you start.

IGMC
I think you'll find it's a bit more complicated than that.

quixoticgeek

  • Mostly Harmless
Re: Tapping off a pipe.
« Reply #2 on: May 09, 2020, 05:01:16 pm »
Does anyone have any advice on such a procedure?
Yes, turn off the water at the mains before you start.

I walked into that didn't I...

J
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http://b.42q.eu/

Re: Tapping off a pipe.
« Reply #3 on: May 09, 2020, 05:26:09 pm »

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: Tapping off a pipe.
« Reply #4 on: May 09, 2020, 05:32:25 pm »

I have a cold feed that currently goes to the shower, I'd like to fit a T piece to it, and run a short spur of pipe to a tap that I can then connect the washing machine to.

The pipe I want to connect to has an OD of 12.7mm. Can anyone suggest what type of pipe I fitting I should be looking for? 12.7mm == ½". But I thought ½" pipe had an OD of 15mm, not 12.7mm.

I'm guessing the tool of choice is going to be a dremel with a cut off disk.

Does anyone have any advice on such a procedure?

J

An actual pipe cutter would be better, subject to how much room you have to work in of course, rotary ones are good, like this type
https://www.screwfix.com/p/rothenberger-15mm-automatic-copper-pipe-cutter/36198

Washing machine t-piece with tap https://www.screwfix.com/p/washing-machine-valve-tee-15mm-x-15mm-x/60723

You can get end feed adaptors to shift the size up or down from 0.5" to 15mm etc.
Regards,

Joergen

Kim

  • Timelord
Re: Tapping off a pipe.
« Reply #5 on: May 09, 2020, 05:47:34 pm »
You can get vampire taps for washing machines that involve fewer plumbing skills: https://www.screwfix.com/p/self-cutting-tap-15mm-x/21250

I fitted one of those for a friend with zero drama.  (The less said about what was growing in the sink drain the better.)  Not sure about your pipe diameter, thobut...
Careful, Kim. Your sarcasm's showing...

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Tapping off a pipe.
« Reply #6 on: May 09, 2020, 05:48:43 pm »
Is this pipe in the UK or NL?  Is it plastic or copper? As you say , so called 1/2 inch pipe in the UK is 15mm OD.  I don't know how they do things in NL.

The pipe cutter and washing machine T piece suggested up thread are the way forward, once questions of pipe size are resolved.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

quixoticgeek

  • Mostly Harmless
Re: Tapping off a pipe.
« Reply #7 on: May 09, 2020, 05:51:23 pm »
You can get 12 mm copper pipe, but 15mm would be better so you can use this
https://www.ebay.co.uk/itm/Reducer-15mm-to-12mm-End-Feed-WRAS-Approved-Copper-Fittings/113952559734?hash=item1a881a1276:g:QlIAAOSwTm1dwtwL

Yeah, I'd prefer to use 15mm pipe, partly as I have other 15mm fittings. Is there any reason not to convert from a 12mm input to a 15mm output?

I can do that in a single T piece:

https://www.gamma.nl/assortiment/gamma-knelkoppeling-messing-t-stuk-12x15x12-mm/p/B425951

Then I can run a 1.5 - 2m of copper pipe, to a wall plate:

https://www.gamma.nl/assortiment/gamma-knelkoppeling-muurplaat-messing-knel-x-binnendraad-15-mm-x-1-2/p/B620236

Then fit a tap like this one:

https://www.gamma.nl/assortiment/gamma-wasmachinekraan-met-beluchter-en-keerklep-chroom-1-2-x-3-4/p/B259170


An actual pipe cutter would be better, subject to how much room you have to work in of course, rotary ones are good, like this type
https://www.screwfix.com/p/rothenberger-15mm-automatic-copper-pipe-cutter/36198

I'd prefer to use a cutter like that. But there's not enough room to get one in. The pipe I want to T off is attached to the wall. There is about 10mm of clearance behind it, and 27mm of clearance to the corner of the wall. This limits my options a lot.

Quote
Washing machine t-piece with tap https://www.screwfix.com/p/washing-machine-valve-tee-15mm-x-15mm-x/60723

You can get end feed adaptors to shift the size up or down from 0.5" to 15mm etc.

I need to run about 1.5m or so to get to the where I want the tap to be, so this doesn't help as much as I'd like. Also seems hard to find here.

You can get vampire taps for washing machines that involve fewer plumbing skills: https://www.screwfix.com/p/self-cutting-tap-15mm-x/21250

I fitted one of those for a friend with zero drama.  (The less said about what was growing in the sink drain the better.)  Not sure about your pipe diameter, thobut...

Would still require a pipe run. I don't think it would be acceptable to my housemate.

Is this pipe in the UK or NL?  Is it plastic or copper? As you say , so called 1/2 inch pipe in the UK is 15mm OD.  I don't know how they do things in NL.

The pipe cutter and washing machine T piece suggested up thread are the way forward, once questions of pipe size are resolved.

This is in .NL. It's 12.7mm with a coat of pain, measuring on a bit of pipe without any paint, I get 12.1, which I'm guessing is 12mm, or as close as.

The pipe cutter thing has the issue of putting the tap output 1.5-2m away from where it's needed.

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Tapping off a pipe.
« Reply #8 on: May 09, 2020, 05:51:48 pm »
You can get vampire taps for washing machines that involve fewer plumbing skills: https://www.screwfix.com/p/self-cutting-tap-15mm-x/21250

I fitted one of those for a friend with zero drama.  (The less said about what was growing in the sink drain the better.)  Not sure about your pipe diameter, thobut...
Ooh, those things are horrible, IM(L)E anyway.  The bit that pierces the host pipe is steel, as it's a cutting tool. After time it rusts to hell and back and the orifice fills up with crud reducing the flow to the washing machine to very sub optimal levels.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Kim

  • Timelord
Re: Tapping off a pipe.
« Reply #9 on: May 09, 2020, 05:59:14 pm »
You can get vampire taps for washing machines that involve fewer plumbing skills: https://www.screwfix.com/p/self-cutting-tap-15mm-x/21250

I fitted one of those for a friend with zero drama.  (The less said about what was growing in the sink drain the better.)  Not sure about your pipe diameter, thobut...
Ooh, those things are horrible, IM(L)E anyway.  The bit that pierces the host pipe is steel, as it's a cutting tool. After time it rusts to hell and back and the orifice fills up with crud reducing the flow to the washing machine to very sub optimal levels.

Ah, I thought the failure mode would be the rubber gasket.  Either way, it was quick and easy and I figured it would be fine for a year or two until the kitchen in question gets re-fitted.
Careful, Kim. Your sarcasm's showing...

Re: Tapping off a pipe.
« Reply #10 on: May 09, 2020, 07:05:41 pm »
You can get vampire taps for washing machines that involve fewer plumbing skills: https://www.screwfix.com/p/self-cutting-tap-15mm-x/21250

I fitted one of those for a friend with zero drama.  (The less said about what was growing in the sink drain the better.)  Not sure about your pipe diameter, thobut...
Ooh, those things are horrible, IM(L)E anyway.  The bit that pierces the host pipe is steel, as it's a cutting tool. After time it rusts to hell and back and the orifice fills up with crud reducing the flow to the washing machine to very sub optimal levels.

Some of those self cut taps are so badly made (or is it actually well made?) that the little circle of pipe came adrift and ended up in a washered tap, as I found once fixing a sudden 'mega dripping tap', though it could be worse if it killed a much more expensive ceramic valve. To my mind the boss should be well offset so cutter leaves a decent 'hinge' to hold the little circular flap forever more, to be fair the self cutter was installed for who knows how long, and the cut/hinge might have lasted decades - if installed by original builder, but they wouldn't do that would they...

Re: Tapping off a pipe.
« Reply #11 on: May 09, 2020, 07:43:19 pm »
The plumbing for my washing machine was thusly executed by whoever lived here before I did.
I cannot tell you how much I wish they hadn't.
It's held together since (I suspect) ~1989 (when the flat conversion was done).
It still doesn't inspire (watertight) confidence.

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Tapping off a pipe.
« Reply #12 on: May 09, 2020, 08:20:19 pm »
You can get vampire taps for washing machines that involve fewer plumbing skills: https://www.screwfix.com/p/self-cutting-tap-15mm-x/21250

I fitted one of those for a friend with zero drama.  (The less said about what was growing in the sink drain the better.)  Not sure about your pipe diameter, thobut...

From experience, others have said, they aren't that great.

You are in Netherlands so I'm guessing that it is 12mm.  Are you competent with a blow lamp and soldering?  The other way is use pushfit pipe t piece.  Such as these https://www.gamma.nl/assortiment/zoeken?text=push+fit&f_type_artikel=T-stuk, then plastic pipe to the appropriate tap fitting.

Re: Tapping off a pipe.
« Reply #13 on: May 09, 2020, 08:42:20 pm »
Compression fitting ought to be fine. You’ll have a happier time with a proper plumbers spanner of the appropriate size.

Is there enough free movement to pull the pipes far enough apart to insert the T piece?

quixoticgeek

  • Mostly Harmless
Re: Tapping off a pipe.
« Reply #14 on: May 09, 2020, 08:45:29 pm »
Compression fitting ought to be fine. You’ll have a happier time with a proper plumbers spanner of the appropriate size.

Is there enough free movement to pull the pipes far enough apart to insert the T piece?

If I undo the screws holding one of the clips in place, there should be.

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Re: Tapping off a pipe.
« Reply #15 on: May 10, 2020, 10:23:13 am »
I've used the vampire taps without issue - although the ones I used were stainless steel, not plain.

Plumbed in a washing machine using them in one house, no issues 10 years later.
<i>Marmite slave</i>

andytheflyer

  • Andytheex-flyer.....
Re: Tapping off a pipe.
« Reply #16 on: May 10, 2020, 02:06:05 pm »
I reckon you might have the old half inch pipe, not the 'new 15mm - they are not quite the same.

I'd cut the pipe with a pipe cutter (as above^^), then fit a compression fitting T, and then you can connect up the washing machine as you wish.

You'll need a modern 15mm compression T piece, but if your pipe really is 1/2", you can get 1/2" olives (the sealing ring in the T piece). They are a bit thicker than the 15mm olives - which will come with the T piece.  The 15mm olives should work though (especially with a bit of plumbers putty in the joint).

So, buy a 15mm T piece, and some 1/2" olives, and then whatever pipe you really have you'll have all the options covered.

The outlet to the washing machine can be a bit of new 15mm, with the washing machine tap on the end.  Simples.


Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Tapping off a pipe.
« Reply #17 on: May 10, 2020, 02:15:47 pm »
I reckon you might have the old half inch pipe, not the 'new 15mm - they are not quite the same.

I'd cut the pipe with a pipe cutter (as above^^), then fit a compression fitting T, and then you can connect up the washing machine as you wish.

You'll need a modern 15mm compression T piece, but if your pipe really is 1/2", you can get 1/2" olives (the sealing ring in the T piece). They are a bit thicker than the 15mm olives - which will come with the T piece.  The 15mm olives should work though (especially with a bit of plumbers putty in the joint).

So, buy a 15mm T piece, and some 1/2" olives, and then whatever pipe you really have you'll have all the options covered.

The outlet to the washing machine can be a bit of new 15mm, with the washing machine tap on the end.  Simples.
I'd bet a guilder the pipe isn't old half inch, as qg is in ABROAD where the FORRINS come from and half inches are rare. Besides, the difference in diameter between 1/2 inch and 15mm copper pipe is small, not the 12mm to 15mm mentioned in the OP.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Re: Tapping off a pipe.
« Reply #18 on: May 10, 2020, 08:11:19 pm »
You should be able to buy tees without pipe stops (slip fittings).

These are much easier to spring into an existing run but you must ensure the tee is centred properly between the cut ends.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Re: Tapping off a pipe.
« Reply #19 on: May 10, 2020, 11:31:05 pm »
I dunno about the Netherlands,  but in France they use bsp sizes.for a lot of pipework.

<i>Marmite slave</i>

quixoticgeek

  • Mostly Harmless
Re: Tapping off a pipe.
« Reply #20 on: May 10, 2020, 11:54:56 pm »
I dunno about the Netherlands,  but in France they use bsp sizes.for a lot of pipework.

Threads are BSP, pipe sizes are metric OD. so 22mm, 15mm, 12mm, 10mm, 8mm etc...

At least for water.

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Re: Tapping off a pipe.
« Reply #21 on: May 17, 2020, 04:17:03 pm »
It's not pipe, it's tube  :smug:
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

robgul

  • Cycle:End-to-End webmaster
  • . . cyclist, Cytech accredited
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Re: Tapping off a pipe.
« Reply #22 on: May 17, 2020, 04:44:23 pm »
I've used the vampire taps without issue - although the ones I used were stainless steel, not plain.

Plumbed in a washing machine using them in one house, no issues 10 years later.

I'd heard about the vampire gadget but never used one until a couple of days ago - I needed to get from a 15mm copper cold water feed through a wall into a cupboard to a valve (inline with a lever) to connect up my coffee machine.   

Screwfix had a connector with an inline valve that exited as a 15mm compression fitting.   Cleaned the pipe, clamped it on with care to get the rubber gasket sitting nicely, wound the fitting into the pipe until it cut and then tightened the locknut.  Perfect .... and amazingly when I turned on the tap at the utility room sink about 2 metres further along the run a sliver of copper popped out.

The access point would have been very awkward to cut and tee off - especially as the copper was connected about 15cm away from one of those awful push-fit things onto a plastic pipe .... in my experience they don't like being disturbed.

Excellent - all done for £4.99 for the vampire, a few odd bits of 15mm copper and 2 fittings from the plumbing toolbox and the coffee machine valve from the previous installation at the old house.

Rob