DIN threads - Maintenance tips

[Nick McV]

I have recently converted to using DIN thread regulators. After a while they build up a thin whitish corrosion, which makes threading them into the cylinder a bit harder than it needs to be.

This may partly be caused by salt water remaining on the threads once the dust cap has been put in place, and this never really gets flushed away in the washing. The cylinders, likewise have this deposit.

Rinsing the regs without the dust cap doesn't sound like a good idea - I don't want water, even fresh water, inside the first stage.

What is the best way of maintaining these threads?

My cylinders are in O2 service (Nitrox up to 32% usually), so I can't put silicon grease on them.

At the moment, I use a soft brass brush to clean them.

[David Walker]

Rinsing the regs without the dust cap doesn't sound like a good idea - I don't want water, even fresh water, inside the first stage.

What is the best way of maintaining these threads?

I just wipe them occasionally, rub a tissue or something around the threads and cleans them up. Of course it won't protect them or anything, just stops the buildup of crap on your threads.

I do find that my main reg, which I use on club cylinders, get a lot more of it than my pony which I only ever use on my own cylinder - the main reg has only been used a couple of times more than the pony. I suppose if the older threads on the club cylinders are more worn then it could be scratching the reg threads a bit?

My conclusion... I don't really know - I thought this was going somewhere when I started typing, but I was wrong :O\ Hehe

Sorry :O)

David

[Rob Meddes]

You can get Oxy compatible grease which i use on the threads but not sure where you get it in Civvy street. You can also get a carbon fibre brush which electricians use to clean contacts. I use this when it gets a bit gungy. Don't know where you get these either.

[tristan green]

You can get Oxy compatible grease which i use on the threads but not sure where you get it in Civvy street.

Try these oxygen compatible silicon greases:

Dow Corning Molykote 111, or
Christo-Lube MCG 111

Regards,
Tristan

[james parrott]

Use an old nylon bristle toothbrush or nailbrush, to clean the threads. grease should not be needed, if the threads are tight, something has been damaged. do not force the threads, these are made to a fairly loose tolerance and will tolerate a fair amount of gunge. for the best result strip and clean in an ultrasonic bath. I would not recomend the use of a carbon fibre/glassfibre brush, these are very abrasive and would with repeated use remove the nickel plating and reveal the brass substrate of the first stage; Then you will learn what corrosion is! to be honest even a brass brush is a bit rough for regular use.

[Squalus]

I have recently converted to using DIN thread regulators. After a while they build up a thin whitish corrosion, which makes threading them into the cylinder a bit harder than it needs to be.

This may partly be caused by salt water remaining on the threads once the dust cap has been put in place, and this never really gets flushed away in the washing. The cylinders, likewise have this deposit.

Rinsing the regs without the dust cap doesn't sound like a good idea - I don't want water, even fresh water, inside the first stage.

What is the best way of maintaining these threads?

My cylinders are in O2 service (Nitrox up to 32% usually), so I can't put silicon grease on them.

At the moment, I use a soft brass brush to clean them.

Hi Nick,

Paint on a little 50% white vinigar/water solution, leave for five minutes them remove with some fairy liquid and a small nylon tooth brush. Try it an you will find the treads come up like new. You should also do this on the inside threads of the pillar valve on the cylinder. You can use a little (I mean little) oxy compatible grease on the threads to reduce future build up.

HTH

Squalus