I'm sure there is a company out there that has sensing equipment they can hook up and read gas % at the end of your system. An internet search may lead you to one in your area or State. Another way would be to pressure test your system. If you don't work in your facility on the weekend, that would be a good time to do it. All the plumbers I've worked with pressure test everything from Gas to water for leaks. In some cases they'll pressure up on Friday, and leave it over the weekend (Providing there isn't a huge 'push' to get the job done). If your facility has 50,000 lineal feet of pipe, finding a leak would obviously more difficult. Contacting the contractor that installed the system might be the way to go, they installed it, they should know how to trouble shoot it. Good luck!

Hey Sloppyjoe!
Make sure you eliminate any possibility of gun components being loose or worn out O-rings, bad liners, clogged diffusers, etc.
Oh yeah, you might want to check for any air drafts.
If the gas analyzer is portable, then take advantage of it...

One more thing that is probably overlooked more than most places and people want to admit is the safety aspect of using a manifold type gas delivery system in a manufacturing plant where alot of argon or CO2 is being used for welding or anything else. What am I getting at?

Last Tuesday the Pittsburgh section of the AWS had a meeting presentation at the BOC Gases National Training Center in Butler, PA. Everyone that attended that meeting was enlightened about how easy it is to become asphyxiated from overexposure to argon and how easy it is to get carbon monoxide poisoning from the use of CO2 if precautions are not taken seriously...

Argon is a very heavy gas compared to CO2, and CO2's byproduct from welding is carbon monoxide!!!

The bottom line is, the HECK with the extra costs of the sensing equipment necessary to monitor and ensure safe levels of O2 or Carbon monoxide in order to avoid poisoning, this needs to be done if they're not already installed and doing their job because, safety must be the first priority especially when you're working with gases that you ca'nt see, smell or can poison you before you can do something about it!!! So please make sure that your O2 levels do NOT go lower than 19% in atmosphere, and make sure you've installed carbon monoxide monitors in your plant.
Otherwise even the people that are'nt even actually performing the welds will drop like flies if unsafe conditions exist inside!!!

Ventilation is'nt enough if the air is'nt being replaced so, do'nt rely on exacuation without replacement and ensuring that the atmosphere has safe levels of EVERY element that makes up the Air we breathe!!!

I kow some people might say: "Well, that only applies to confined spaces." My response to that is: "The atmosphere only has 22% O2 so even a slight drop in percentage can cause an unsafe and potentially tragic situation in any enclosed location that none of us want to answer for in court."

I hope I scared some people enough to rethink their safety plan because, that sure was the intent at the meeting last Tuesday!!!

Good luck with your troubleshooting Sloppyjoe!

Respectfully,

SSBN727 Run Silent... Run Deep!!!
Oh yeah, do'nt forget to breathe - clean air that is!!!

You might also try waiting until they change out the tank and try again. Especially if your employer goes for the bargain company. We get trash gas periodically.Cant even weld with it. Makes nasty welds and welding overhead nearly impossible. Since the company has given us bad gas on numerous occasions,it is always my first suspect when things go wrong.
I also was told that when the tanks go back to the plant,sometimes they open them and condensation is able to form inside. Nothing more fun than welding overhead on anodized aluminum with a little H2o in the mix.

A number of years ago, I was given some information on Draeger tubes. Those are small glass cylinders filled with different compounds intended to test for various substances. They are one shot deals meaning you need a new tube for each test but they may not cost that much.
Usually the tubes test for only one chemical or familay of chemicals and change color when there is a positive indication.
I don't know if price and availability make them worthwhile over some sort of gas analyzer or not.
I was thinking you might look into obtaining some made for testing nitrogen since that is the largest percentage of gas in air.

I wouldn't think you would be "sucking air" into a pressurized system, unless you shut off the supply at night. I would check and see if any maintenance was done recently. Possibly something wasn't purged properly? It takes a surprisingly large volume of gas to be sure contaminants are voided from the internal 'nooks & crannys'. Sometimes, well intentioned people take shortcuts because they don't understand the consequences. If that could be the case, then a system purge might be better than waiting for test equipment and test results.

Chet Guilford