Particle contamination is a common problem with airguns. It's one of the primary causes of valve leaks. It can also cause regulators to fail. Components should be checked before installation to make sure they're free of potentially damaging particles.

 In the photos above, you can see a small gold-colored piece of sintered filter embedded in the sealing face of a valve stem. The filter itself can be seen in the fill nipple of the regulator. That particle ended up behind the pin valve as the regulator was assembled. It was blown into the gun when the tank and regulator were threaded into the tank block. It was on it's way through the valve when the stem closed on it. This not only damaged the stem but the Magnum Valve which had a deep pit where the stem seats. Both parts needed to be replaced. It was a costly repair for the customer who put a contaminated regulator on the custom HPA gun he bought from us.

 Metal filings left over from machining and grit from abrasives used to deburr and polish are common contaminants. Every component of our parts and guns are clean when shipped. Make sure parts are still clean before installing them. Keep your gun and related equipment clean to avoid internal contamination.