I've been doing a little bit of MDPE plumbing just recently and it's
not going well.

Previously I've not had big problems with getting watertight and long
term reliable connections. I have quite a lot of MDPE buried across
our fields feeding two horse waterers and a couple of taps for
greenhouses etc. All fairly straightforward and reliable.

Now I am trying to tee off an existing feed (quite recently installed
by a builder) to an outside tap to provide a feed for our chcickens.
We only have 9 chickens but daily checking the water is a chore. We
moved them recently and they used to have an automatic waterer and we
want it back!

So I've added a tee to the existing blue pipe, run a pipe across a
path, put a stop tap in and then it runs to the chickens.

One tee, two elbows and an in-line tap, simple - no.

Various problems:-

I bought some floplast inserts from Screwfix, they are too tight
in the MDPE I have, you can't push them in by hand and so when
they need to go somewhere a bit inaccessible they are a complete
pain. The older (white rather than black) inserts I have go in
much more easily. I've ordered some more, not Floplast, inserts

The in-line tap I have is almost impossible to install on pipes
with Floplast inserts (at least I think this is the problem). The
plastic rings that push against the sealing rings expand such that
the retaining nuts can't be screwed onto the body of the tap. A
bit more thread on the tap body would make things much easier.

Pushing the MDPE pipe into the standard O-ring sealed fittings
seems more difficult than it should be, I've not found it so
difficult before, am I getting feebler (probably) or is there
something I can do to make it easier?


I guess it's mostly down to less accessibility than I've had on
previous occasions, slightly too big Floplast inserts and a mixture of
brands of fittings.

Any advice or comiserations would be very welcome! :-)

--
Chris Green
·

Chris Green wrote:

Any advice or comiserations would be very welcome! :-)

In the last 18 months I've used quit a few JG 25mm speedfit fittings

(1xTee, 3xTap connector, 2xStop taps, 2xStraight connector, a bag of
inserts) they're not cheap especially the valves, but no problems ...

On 25 Apr 2021 at 09:44:47 BST, "Chris Green" wrote:

I've been doing a little bit of MDPE plumbing just recently and it's
not going well.

Previously I've not had big problems with getting watertight and long
term reliable connections. I have quite a lot of MDPE buried across
our fields feeding two horse waterers and a couple of taps for
greenhouses etc. All fairly straightforward and reliable.

Now I am trying to tee off an existing feed (quite recently installed
by a builder) to an outside tap to provide a feed for our chcickens.
We only have 9 chickens but daily checking the water is a chore. We
moved them recently and they used to have an automatic waterer and we
want it back!

So I've added a tee to the existing blue pipe, run a pipe across a
path, put a stop tap in and then it runs to the chickens.

One tee, two elbows and an in-line tap, simple - no.

Various problems:-

I bought some floplast inserts from Screwfix, they are too tight
in the MDPE I have, you can't push them in by hand and so when
they need to go somewhere a bit inaccessible they are a complete
pain. The older (white rather than black) inserts I have go in
much more easily. I've ordered some more, not Floplast, inserts

The in-line tap I have is almost impossible to install on pipes
with Floplast inserts (at least I think this is the problem). The
plastic rings that push against the sealing rings expand such that
the retaining nuts can't be screwed onto the body of the tap. A
bit more thread on the tap body would make things much easier.

Pushing the MDPE pipe into the standard O-ring sealed fittings
seems more difficult than it should be, I've not found it so
difficult before, am I getting feebler (probably) or is there
something I can do to make it easier?


I guess it's mostly down to less accessibility than I've had on
previous occasions, slightly too big Floplast inserts and a mixture of
brands of fittings.

Any advice or comiserations would be very welcome! :-)

Did you use silicone spray, and chamfer the tube ends a bit?

--
Roger Hayter

Roger Hayter wrote:
[snip]

Pushing the MDPE pipe into the standard O-ring sealed fittings
seems more difficult than it should be, I've not found it so
difficult before, am I getting feebler (probably) or is there
something I can do to make it easier?


I guess it's mostly down to less accessibility than I've had on
previous occasions, slightly too big Floplast inserts and a mixture of
brands of fittings.

Any advice or comiserations would be very welcome! :-)

Did you use silicone spray, and chamfer the tube ends a bit?

I've started using silicone spray as I had a can on the shelf, it does
seem to help a bit but I've not had to use it before. I've not been
chamfering either, it shouldn't be necessary should it really? I'm
using a 'knife type' pipe cutter so the ends are very clean with no
burrs.

--
Chris Green
·

On 25/04/2021 09:44, Chris Green wrote:

Now I am trying to tee off an existing feed ...
Many moons ago, visiting an ex girlfriend's parents, her dad was trying
to get mains water to his greenhouses, he'd worked out where the supply
to a row of terraces was and dug down to get at the pipe.

The plan was to turn the water off for as brief a time as possible*, cut
the pipe, tee off, back on.

*Given that for obvious reasons this was being done in a clandestine
manner and on a strict need to know basis.

I can't remember exactly the make up of the fittings but there was a
screw on locking collar that needed to go over the pipe *first* before a
ring and an insert but in the necessary haste he'd omitted this,
realised his error and couldn't get the other bits off/out of the pipe
to rectify.

Hilarity ensued while half the village probably wondered why they were
without water, me face down in the hole at arms length with a kettle of
hot water and a variety of whacking and prising implements.

On 25/04/2021 09:44, Chris Green wrote:

One tee, two elbows and an in-line tap, simple - no.

Various problems:-

I bought some floplast inserts from Screwfix, they are too tight
in the MDPE I have, you can't push them in by hand and so when
they need to go somewhere a bit inaccessible they are a complete
pain. The older (white rather than black) inserts I have go in
much more easily. I've ordered some more, not Floplast, inserts

Not really that relevant, but I have found the floplast fittings for
15mm pipe are also a bit on the tight side for my liking - taking quite
significant force to get the pipe inserted to the right depth.

ISTR the last time I did MDPE it was fine - but that was defnitely not
floplast.


--
Cheers,

John.

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On 25/04/2021 12:16, Chris Green wrote:
Roger Hayter wrote:
[snip]

Pushing the MDPE pipe into the standard O-ring sealed fittings
seems more difficult than it should be, I've not found it so
difficult before, am I getting feebler (probably) or is there
something I can do to make it easier?


I guess it's mostly down to less accessibility than I've had on
previous occasions, slightly too big Floplast inserts and a mixture of
brands of fittings.

Any advice or comiserations would be very welcome! :-)

Did you use silicone spray, and chamfer the tube ends a bit?

I've started using silicone spray as I had a can on the shelf, it does
seem to help a bit but I've not had to use it before. I've not been
chamfering either, it shouldn't be necessary should it really? I'm
using a 'knife type' pipe cutter so the ends are very clean with no
burrs.

Another +1 for silicone spray on tight plastic joints. One issue with
O-rings is that once you damage them you risk having a flow path.