polybutylene plumbing

[Sam]

Hello,

I am about to make my first attempt at plumbing with plastic pipe. I am a bit confused about what fittings to use. I know to use the correct Pb or PEX inserts.

I know I can use standard brass compression fittings and some of the push fit for copper fittings say you can use them on plastic pipe too, but I see there are also plastic push fit fittings: are these just to join plastic to plastic or can they be used to join plastic to copper?

What is the best to use: compression? Are we still paranoid about push fit? ;)

TIA

[Doctor Drivel]

Use good quality brass compression.

NHBC now stipulate that plastic pipe be wrapped in foil insulation, so metal detectors can locate the pipe in walls and floors. May as well use copper to begin with and use plastic for awkward situations.

Bes Part no: 17584

to the documentation for metallic tape with Hep2o: $FILE/Hep2O_Metal_Tape.pdf

[Sam]

I quite agree. It is for an awkward situation: running CH between joists!

[Sam]

Sorry to reply to myself but looking around, the cheapest pipe seems to be the Flopast PEX in Screwfix, part 54479 and 38914. I would have preferred PB rather than PEX as I had read here that Pb was more flexible. Are these prices good, and can I find better anywhere else?

Has anyone used Flopast pipe; is it any good?

Also, I understand you need a special pipe cutter to cut Pb and PX pipe. Can anyone show me a suitable (and cheap) one in Screwfix, so that I know what I am looking for?

Thanks.

[Grumps]

Before Dr D replies, ignore him if he points you to one of these:

[Sam]

Thanks. I think I need something like part no. 59590 or the twice as expensive 38389. For some reason I didn't find them last time I looked.

[Autolycus]

I've used several brands, and not noticed any difference. Perhaps in a few years the difference will show up in the scale of the flooding. JG admit Speedfit can be mixed with other makes, but say that you should use the correct inserts. Note that Screwfix don't make it clear that you should (according to JG) use the inserts without the O-ring seals when you use compression fittings. JG also warn against compression fittings with only a shallow pipe engagement (e.g. some isolating valves).

Screwfix 59590 or Toolstation 69222 - or many market stalls.

BES are worth checking for prices - some stuff is cheaper than Screwfix, and their minimum quantities are more sensible. You can buy one olive, for instance.

[fred]

In article , Sam writes

The cheapie is fine for light use, mine was a tenner or so and of similar design and has worked fine for 15mm pipe and 25mm water main pipe.

I assume the second cutter was 34389

Just apply pressure smoothly and let the blade do the cutting.

I've only used PE-X so can't comment on PB but PE-X is pretty stiff, I used JG Speedfit brand but bought it in quantity when it was on special so got a good price. I wouldn't necessarily buy on price alone, compared with the cost of other plumbing items/fittings, plastic pipe is cheap so will contribute less to the total cost of the job.

[John Stumbles]

Dunno, I use the Qualpex PB from screwfix which is cheap enough and nice and flexible, whilst being a barrier pipe.

You can get away with a nice sharp pair of bypass secateurs (the sort where the blades are like scissor blades but parrot-bill shaped). I did for years before biting the bullet and buying 'proper' plastic pipe cutters. The proper cutters are a bit easier to start a cut with.