Will a thread adapter on CO2 regulator withstand pressure?

[snafuspyramid]

Hi guys,

I've got a regulator for use on a 1.6kg CO2 bottle. The output pressure is 900psi.

The regulator is a solid brass, German made unit of exceptional quality.

Unfortunately it is not made to fit Australian cylinders.

To remedy this, I need to fit a new spigot (bit that attaches to cylinder).

To do that, I need to convert the thread in the regulator body from 5/8 - 18 UNF to 1/4BSPT, or something similar - I'll find out exactly what the thread is from the manufacturer shortly.

Supagas sell a brass adapter that should work fine. It looks like this:

BSPT.jpg

However, the guy there warns that, in his opinion, there's a risk it might not withstand the pressure and pop off.

This doesn't seem at all likely to me. It looks far more solid than the connection on any aquarium CO2 regulator I've ever come across (most of which are a little more than hand-tight).

Alternatively, I could find an adapter from a female Part 30 fitting (the connection to the cylinder) to a male 5/8-18 UNF (for the connection to the regulator). This would work better, but I don't know where to find something like that.

[dubman]

If the guy who is selling it thinks its dodgy it most likely is
Bring the whole regulator to your local Welding supply shop
They should have a spigot (or be able to get one) that will fit
Most cases they will fit it for you (not BOC because they are not allowed do stuff anymore)

[gallegos]

So the new spigot to suit the cylinder is a 1/4 BSPT male thread and the port in the regulator is 5/8 UNF and your looking at using brass reducing bush to make them fit?

I can't see why this would be a problem given that each of the parts have these threads already and are obviously designed specifically for CO2 service. Also I'm assuming the reducing bush is the same material and will fit more or less completely inside the regulator port. Cant see the problem with this myself... did the guy say why he didnt think it would work?

The only thing to watch, with the tapered thread in particular, is that you want to ensure the thread is identified correctly and there is good engaugement. If its mismatched or poorly machined it wont thread in very far before binding then it might be a bit iffy.