CO2 Tank Pressure Question - Am I Safe?

[thompsdw]

I had my stock Danby CO2 tank (5lb) refilled a couple days ago and had something wierd happen. The filled pressure of the tank was right at 1,500 psi. I thought it was supposed to be more like 900 psi at ~70 F. So, I decided to check weight. The tare weight stamped on the tank is 7.5 lbs and the filled tank weight is 11 lbs 0.8 oz on a certified scale (I double checked on a bath scale). So the CO2 weight is a little over 3.5 lbs. Far short of the 5 lbs I expected.

I suspected the regulator, so I decided to purchase a new premium regulator set. I received my new regulator today expecting to see less than 1,500 psi at 70 F. The pressure was the exact same. I do completely understand the pressure versus temperature issue, but how can my pressure be that high with a low cylinder weight? I know that two pressure gauges are not wrong! My garage gets to 90 F in the summer, so I can assume that the MAWP of 1,800 psi on the bottle will be compromised when things heat up!

Help! I just want to make sure I don't have a safety issue. I have already decided to change my CO2 supplier .... can gas contamination (non-condensible gasses?) cause something like this? I'm just not sure what to do next ...................

 

[beninan]

The tank pressure gauge (not the regulated pressure gauge) is practically useless. If there is ANY liquid CO2 in the tank, the pressure will be off, and temperature only helps to add more confusion. If you put the tank in the refrigerator, the pressure will drop.

HOWEVER!!, I would recommend taking the tank back to where you had it filled. I'm no expert on gas pressures by any means, so that amount of pressure may be unsafe. It may be normal as well, but at least a certified gas specialist (if that's what they are called) will be able to tell you.