Safe Sampling – How we do it (update 6/2004)
A Quick Summary Bulletin #24
Sampling compressed air can always be dangerous. Preventing an injury from the improper use of our sampling kit is accomplished with 2 built-in pressure relief devices that prevent over pressurization.
Safety Tests
The potential danger from sudden exposure to high pressure became personal when a friend of ours was injured using a competitor’s sampling kit. An important part had been left out of that kit, and the kit exploded. This can’t happen with out kit. During development of our sampling kits, we tested them in every way possible. The end result of our research program was a design that protected the parts by completely preventing over pressurization. We did this without compromising the ability of the sampling device to take a proper and meaningful sample.
We accomplished this with a re-seating pressure relief valve which activates at 40 psi. We include a sacrificial rupture film on the sampler block that pops at pressure above 160 psi. Some of our accessories have additional over pressure protection. Although our sampling protocol is to reduce the compressed air system to about 300 to 800 psi before connecting the parts of our kits, we wanted to be certain that the kit would survive accidental pressures at 3400 psi.
We perform these tests by connecting the assembled sampler block directly to the outlet of the main valve on a 3400 psi industrial gas cylinder. We then suddenly opened the cylinder valve to instantaneously bring the full pressure and enormously high air flow into the sampler block. This proved that all the safety features worked to prevent a problem. A video tape of this is available.
In short, neither the sampler block nor the canisters in any of our sampling kits can be over-pressurized during normal use.
We hasten to add that attempting to modify any of our kits is never necessary; to do so would probably defeat the safety features that are a permanent part of the kit and render it useless.