Plastic BSP fittings - confused

[gasket999]

Quick one folks.

Some years ago I bought a few manifolds for a workshop air system and I’m finally fitting them.

The plan is to have the air come in from the top, a line leading to a ball valve coming from the bottom (for drainage) and three quick connects in different formats coming out of the front.

No worries there. Except one of the female threads in the manifold (the top one) is just plastic and doesn’t have a brass insert. It’s obviously part of a proprietary airline system, but I just want to use it with 15mm copper pipe.

Could anyone advise how best to use this port? I’m not sure whether to just carefully use brass BSP (taper) male fittings, whether to buy some sort of plastic make fitting or to just block the port with a plastic/brass bung and use the manifold upside down (I have plenty of other drops and drains in the system).

Any help would be very welcome - the last thing I want to do is to tear the threads and ruin the manifold.

Thank you.

 

[Kram]

If its bsp and all the same threads, Id suggest plastic is intended to be fitted once and not disturbed, while the others you can swap often as you like.

Use ptfe tape as sealant on the plastic rather than liquid - I prefer threadlock for metal threads.

 

[Kayos]

Or use a blank in that one

 

[Agroshield]

...I'd suggest plastic is intended to be fitted once and not disturbed, while the others you can swap often as you like.

What he said. You can imagine the supply coming in on a rigid line from above, with the supply pipe clipped to the wall and the manifold screwed to the wall. Then flexi hoses could go out from the brass-inserted ports.

 

[frank horton]

I wouldn't worry ....it wont be made of cr@p plastic....
use a brass stud first and ur airline fittings into the brass....

 

[gasket999]

Thanks all - good to see there’s some solutions.

I’ve been having a good look at the routing for my pipework (it’s very tight as I already have 13a, 16a and 32a electrics and sockets running in conduit), and it would actually be better for me if the manifolds were fed from underneath.

That way, there is no concern about needing a drain for the manifold as I can have my drops in another place.

…which means that if I can simply find a plastic 1/2” BST taper male bung then I can pop that I the top.

Just about to go through the John Guest airline catalogue to find one.

 

[julianf]

I'd suggest it may not be a taper fitting.

Plastic are, in my experience, more frequently parallel. The plastic can not take the force of a taper "wedge" in the same way and, if you're not careful with a taper male fitting, you will crack the job.

I would suggest considering a parallel thread sealing on a washer, rather than trying to seal on the thread as you would a taper.

 

[mike os]

Search tefen nylon fittings

They are 10 bar rated

All are taper,

 

[julianf]

Search tefen nylon fittings

They are 10 bar rated

All are taper,

For clarity, are you saying that the above fitting it a tefen nylon part or similar?

Your response seems to be to me.

At no point did I say that taper plastic fittings might not exist, just that many plastic fittings did not have the strength to seal on the thread and should be used with a sealing washer.

I'd stand by this statement.

If you are saying that the above is the tefen part, or another similar, that is fine.

But if it's an unknown, I would stand by my comment that it may not be a great idea to tighten down a taper fitting into the unknown part.

 

[knighty]

I'd have sealed it with a washer too

if they're 1/2" bsb just go with brass water fittings, any decent plumbing place will stock them - you just need one that had a shoulder for the rubber washer/o-ring to seal against

 

[piman]

Hello gasket999,

simply use a push fit 15mm male fitting (John Guest style), they come with an integral sealing washet designed for that type of use.

Alec

 

[Brad93]

those fittings are for the push fit airline systems which use plastic connectors. The piping is plastic with an aluminium layer.

 

[gasket999]

Thanks very much everyone.

Only got a couple of hours on the airlines this weekend, working from the compressor out.

The dryer/drops are now done, will work toward the manifolds next weekend and will report back how I get on.