Glue for plastic oxygen pipe

[Harry Bloomfield]

I need to modify some medical oxygen plastic pipes, just like the pipe used for fish tank air pumps. The similar plastic ends need to be glued in place. What would be a suitable glue please?

[Andy Burns]

For a /medical/ application, or just re-using the pipe for something else?

[Harry Bloomfield]

Medical - oxygen supply pipe.

[polygonum]

I would be surprised if all oxygen supply pipes are made of the same plastic. Therefore you need first to identify the polymer(s). Actually, if intended for medical application, I would contact the manufacturer of the original pipe. It can be important to get these things right.

[newshound]

A lot of medical pipes are silicone, which is difficult to glue. I have a vague recollection that oxygen pipes may be PVC, in which case solvent glues should work, and *should* be safe once all the solvents have evaporated. But normally the push-fit connections are considered secure enough. If your problem is that push fit connections are getting pulled out another strategy might be to tape them together.

[Bernard Peek]

If you don't know that I suspect that you probably shouldn't attempt it without supervision. I suspect that you aren't permitted to make changes or repairs except under supervision, if at all.

[Nightjar]

The preferred material for flexible oxygen therapy tubing is PTFE, because of its low reactivity with oxygen and its high ignition temperature. Fluoroelastomer, nylon and polyethylene are possible, although less preferred, alternatives. Joints are normally made mechanically, with external clips if necessary, and I seriously doubt that the use of adhesives would be advisable.

[Part Timer]

Don't bother joining lengths of pipe. Is this what we call "bubble tube" in the trade in that it widens out at regular intervals, allowing you to cut it at a suitable point to fit on variously sized supply outlets, cylinders, masks, etc. Ask the hospital etc to cut you off a piece from the box (it's supplied like CAT5) of the length you need.

[Nightjar]

Bubble tube is one form of flexible oxygen therapy tube, but it can also be of constant diameter. It is often coloured green for ease of identification.

Bubble tube is said to have been an accidental invention, when sombody noticed tubing that had been badly made had varying diameters and realised that could be made into a feature.

[Harry Bloomfield]

Well thanks for the replies and suggestions...

The tube is just clear, straight sided and about 6mm diameter with a plastic adaptor on each end and a flame trap. I cannot see any signs of glue, but the parts do seem to be very firmly attached.

SWMBO now needs almost constant oxygen, which is provided from a large mains operated oxygen generator. When we go off in the caravan, the idea is to be able to put the generator in the bathroom at the rear of the van, with the beds at the front. On our last trip, that involved the tube and power running front to back along the caravan's corridor, which is a bit of a nuisance.

My idea is to semi- permanently install a pipe and power between the two points, so they are well out of the way.

[newshound]

Sorry to hear that. Sounds reasonable to me. My late FiL who was a very practical guy rigged up oxygen access all over the house with catenery hoses, but just using the standard connectors when he moved around. I still have some of them somewhere.

[Nightjar]

On 23/06/2014 10:23, Harry Bloomfield wrote: ...

In that situation, it would be a lot safer to use copper tube, with quick-fit connectors at each end. Oxygen is a very dangerous substance and vibration alone can generate enough energy to cause combustion in some materials.

Ideally, buy copper tube that has already been de-greased for use with oxygen. Otherwise you need to ensure that every bit of grease, other organic material and foreign particles have been removed from the inside before capping the ends, to keep the bore clean. Fit it in place, then add oxygen approved quick-fit connectors.

[newshound]

But remember, this isn't 100% oxygen, although I can't recall the concentration off-hand. I would have thought that with a *continuous* run of "proper" flexible pipe between the generator and the point of use, routed sensibly (behind paneling? surface mounted with P clips and self tappers?) that there isn't really a risk. Since the generator runs on mains it can only be used when the caravan is static. I agree, if you were running a system from cylinders in a camper van or boat then suitable mechanical protection would be much more important.

The generators are quite noisy and separation is certainly a good goal.

[Fredxxx]

If we were talking 100 bar or so I would agree. But near pure oxygen at atmospheric pressure is rarely a problem.

[Bernard Peek]

That includes copper. This really is not a suitable job for DIY.

[Nightjar]

93% according to one manufacturer. Pure enough to be a serious fire hazard.

The aim is a high ignition or melting point for the tubing. Stainless steel would be better from that point of view, but most people would find it more difficult to handle.

[newshound]

Well, not quite true in an enclosed space with an ignition source and combustible material, as the Apollo programme discovered.

But the difference here is that even if the generator is delivering 93%, it is still only delivering at (I guess) something like 1 psig through perhaps a 4 mm bore pipe. So the concentration at any distance from a leak will not be high. OK, not something you would want to deliver into the bilges of a boat, but strung across the ceiling of a caravan with no joints except at the ends doesn't seem *that* risky to me. Especially if there are a couple of smoke detectors, and considering the difference it makes to someone's quality of life.

[dennis]

8<

The last time I looked at oxygen tube it has ridges along the inside of the tube so you can't get a good seal by pushing it onto something. You get plastic adapters that seal to the outside with glue. It bonds instantly so its either a solvent or "super" glue.

My dad had a battery operated concentrator, much better than trying to take a full sized one anywhere. They even used it when he had his cateract op as it saved him waiting for a room with oxygen.

[Harry Bloomfield]

Dennis@home explained on 23/06/2014 :

That is something we have heard rumours of, but so far no details. Are they lighter/smaller than the mains powered ones? Would they be of any use in a caravan long term?

[polygonum]

You could do worse than go to Amazon and type in "oxygen concentrator".

Quite a bit of information by reading the appropriate listings.