Sciencemadness Discussion Board

Gas regulators

itchyfruit - 21-1-2010 at 12:34

I recently acquired some laboratory gas samples and was wondering/presuming they would need a regulator of some sort the canisters are from sigma Aldrich and are about 10" * 2" CL2 and NH3.
Assuming they do need a regulator does anyone know where i might get one.
I tried sigma and fluka but couldn't see one in their catalogues.

watson.fawkes - 21-1-2010 at 13:46

Quote: Originally posted by itchyfruit  
I recently acquired some laboratory gas samples and was wondering/presuming they would need a regulator of some sort the canisters are from sigma Aldrich and are about 10" * 2" CL2 and NH3.
Assuming they do need a regulator does anyone know where i might get one.
I tried sigma and fluka but couldn't see one in their catalogues.
Go to a commercial gas vendor that handles these gasses. They'll know the materials compatibility issues and will also sell regulators and fittings. I seem to recall that stainless work for both of these, but don't rely on my immediate memory for your safety. The lecture bottles you've got don't take particularly special sizes.

gsd - 21-1-2010 at 17:57

AFAIK MS will work for both but Stainless Steel is best. One thing is sure, Brass and Copper are absolutely not compatible with NH3. As advised by wf it is prudent to talk to a regulator supplier. That will also help you in getting the fittings with matching threads.

gsd

itchyfruit - 24-1-2010 at 11:05

I tried BOC and their going to get back to me with prices as are fisher, but i suspect new ones are going to be expensive.

Can anyone recommend a second hand source.

itchyfruit - 25-1-2010 at 07:28

As i suspected around £700 each

Does anyone know what sort of pressure's are in these canisters ?

watson.fawkes - 25-1-2010 at 09:15

Quote: Originally posted by itchyfruit  
As i suspected around �700 each

Does anyone know what sort of pressure's are in these canisters ?
Here's a bit cheaper one: http://www.labregulator.com/corrosive.htm. One of the problems with shopping for these is that most prices are quoted, rather than posted, and you'll likely be paying the "I don't care about you" price for small customers. Go in person, explain yourself, and ask for a discount. It will be the "interesting person" discount. Be sure to ask for and respect their expertise about their business, otherwise you'll get the "full of himself" non-discount.

Both the gases you mention are stored as liquid inside the bottle, as they have fairly high boiling points. Pressure is thus the vapor pressure at ambient temperature. Here's some data on chlorine; pressure at room temperature is around 90-100 psi. Ammonia is about 1-1/2 times this.

itchyfruit - 25-1-2010 at 10:17

Cheers for the link and advice W.F, but it still works out to be a lot of money for a few flasks of chlorine for reacting Al Fe P Mg Etc in (i can't even think of a use for the ammonia) i know i can produce small amounts of chlorine for this purpose, but thought seeing as i have these canisters i might aswell make use of at least one of them.

Whilst watching 'the periodic table of videos' i noticed the only regulator they had on their Cl2 canister looks rather like a simple needle valve, i'm sure this is all i need and was thinking i could get something very similar from a hydraulic suppliers.

Any thoughts!!!

watson.fawkes - 25-1-2010 at 13:20

Quote: Originally posted by itchyfruit  
Cheers for the link and advice W.F, but it still works out to be a lot of money for a few flasks of chlorine [...] Whilst watching 'the periodic table of videos' i noticed the only regulator they had on their Cl2 canister looks rather like a simple needle valve, i'm sure this is all i need and was thinking i could get something very similar from a hydraulic suppliers.
What you are talking about, I suspect, is what's called a single-stage regulator. the link I posted was for a two-stage regulator. They're certainly cheaper, but they don't provide constant gas pressure by design. Now for tanks with liquid contents, this isn't nearly the problem it is with high-pressure tanks, since their vapor pressure is constant if the tank temperature is.

eBay is a reasonable source for regulators, I've found. Still, once you've acquired one, you'll want to trek down to your local gas supplier with your tank and your regulator and let them help you get the rest of the piping you'll need, which is likely just a threaded adapter between the bottle and the regulator. If you get lucky you might find one already outfitted for lecture bottles. If not, the piping is cheap compared to the regulator.

I should point out that if you only need one gas at a time, you can get by with only one regulator. If you do this, be sure to purge it with a dry, inert gas between uses.