Making a Link Pipe Help

[geoffsurf]

If the threads are actually BSP at both ends I would be tempted to use a couple of BSP to copper adaptors and join them up with copper pipe, then you can do what you want with it, increase it's size, extend it as long as you want and add an expansion tank in the line if required.
https://www.bes.co.uk/straight-coup...MI5tvxkdWW3AIV7bvtCh38NwR7EAQYBCABEgLDNfD_BwE

https://www.screwfix.com/p/male-cou...gclsrc=aw.ds&dclid=CNL_9Z7WltwCFeYC0wodlKoHAw

If you look at the top and bottom photos I posted you can see that the top photo shows the NRV with the tapered fitting. The elbow fitting at the pump also has the same thread and tapered fitting.

The fittings that you provide links for look like they are for sealing threads where there is no taper and rather just seal when bottoming out. I don't see how the fittings will seal on the NRV and elbow at the pump?

 

[knighty]

scrap what I said about the coils of 15mm pipe... cheapest I can find is £140 :-o

:-(

 

[hunter27]

If you look at the top and bottom photos I posted you can see that the top photo shows the NRV with the tapered fitting. The elbow fitting at the pump also has the same thread and tapered fitting.

The fittings that you provide links for look like they are for sealing threads where there is no taper and rather just seal when bottoming out. I don't see how the fittings will seal on the NRV and elbow at the pump?

It's a bit suck it and see really but I would try sealing the thread with PTFE tape first depending how many threads you can get on but some times fitting a fibre washer in the bottom of the fitting and tightening down onto that works. Fittings often have different inside profiles depending who makes them so some are not suitable for doing this.
Or try a 1/2" X 15mm tap washer with the spigot filed off and a fibre washer installed.

https://www.diy.com/departments/end-feed-bent-tap-connector-dia-15mm/262038_BQ.prd

They also do them straight and compression.
I have a garage full of plumbing fittings so obviously that is what I try first

 

[geoffsurf]

Thanks for the replies. I had a think and tried calling an air supplies company that I found on google. The man there was very helpful and explained pretty much what you are talking about. So now I understand what you are saying. When I previously took my parts to a local place I think they said that without the taper fitting at the end of the thread it wouldn't seal just using the thread.

I have some thick gas PTFE tape and just got a load of various male and female 1/2" compression fittings, including some tap fittings to try and see what the best solution is. The only remaining questions I have is whether it is better to try and bend the straight pieces of copper pipe using a pipe bender or to cut straight pieces and then use compression fittings to create coils/bends?

Looking at the whole compressor, would it be better to just do some very short tight vertical sections right between the pump and the tank NRV where the original pipe was. Or would it be better to go over the top of the pump to the switch and back again to the other side in long horizontal sections?

 

[awemawson]

If your input mains is too low as you say that are on the end of the line so to speak, fit an auto transformer to up the volts a bit.

Any biggish transformer with taps on the primary can be used. Put your incoming mains on the 220 volt tapping (for instance) and take your output from the 240 or 250 volt tapping

 

[knighty]

can you not fit a tee piece to the existing pipe, then have something coming to increase the air volume?, bit of pipe, some sort of small tank/whatever?

I wonder if a 15mm copper tee piece would solder on? - or maybe fix on some other way?

could use a 15/22/15 unequal tee, so you could have a bit of 22mm copper pipe stick up in the air (or wherever... maybe along side the compressor?)

22mm would mean you wouldn't need as much length

to be honest I'd be very tempted to use a bit of rubber pipe and jubilee clips but the pipe/air probably gets a bit hot for that

 

[Al Strachan]

As per above, I’d just be teeing into the plastic blow off line to the switch and fitting a small auto draining water trap. Two 6mm to 3/8 bsp push fittings and cheapo trap from the ‘bay. An auto drain one would be ideal where it doesn’t seal until there’s pressure. No messing with hard pipe.

 

[geoffsurf]

Sorry for the long delay in updating and responding. I read all the posts and realised that teeing into the plastic blow off line would be a good way to do it. I am not sure if the auto drain would seal very quickly or stay open enough to do the job.

However, what I hadn't explained is that I had already cut the existing pump to tank feed pipe in half because a local place suggested creating an extension in the middle of the feed pipe by adding a section of rubber air hose with clips. Well I tried this before posting this thread and at around 100 psi the hose came flying off, not to mention the fact that the air hose (rated to 300 psi) was expanding quite a bit.

I therefore needed to sort the pump to tank feed pipe anyway. I decided to try making one up with 15mm copper pipe and a pipe bender I borrowed. I managed to bend a single piece of copper pipe so that it goes right around the compressor making the link pipe longer. It is just short of a 3 metre piece of copper pipe. I then went to screwfix and bought various 15mm compression fittings with 1/2 inch thread. I found two that fit either end of the link pipe and the taper on the threaded ends nicely mate the taper on the existing pump and NRV thread.

Initial tests starting the compressor and filling it before leaving it for some time to cool, and then draining it to make it auto restart have suggested the longer link pipe works and has cured the problem. I need to test it more with actual use but it seems good. While the link pipe I made might not be the most amazing job I am quite impressed with it for a first attempt at bending copper pipe. I have used various 15mm copper pipe brackets to brace the link pipe against the fan shroud/cover. This was the easiest place to brace the link pipe, and I have added a brace between the shroud and the main tank plate. My only concern is the vibration over time cracking or weakening the copper pipe, but I have tried to reduce this risk by bracing the shroud to the tank plate.

 

[geoffsurf]

 

[awemawson]

Make sure that you kill ANY vibrations in the copper pipe or it will work harden and crack over time

 

[dai]

To stop the copper breaking put a coil in the pipe to absorb the vibrations