A question I get not nearly enough, and when I do, the party that asked it is usually not happy with my answer. But when we pressure test our piping pneumatically, we MUST establish a “safe distance”. And simply stated, the distances START @
140′ (50 m) and go up to 2,000′(605 m).
These distances are 360 degrees around the piping being tested. Some walls/floors/roofs may be adequate barriers of separation, but MOST will NOT BE adequate and, in fact, will only create more projectiles to cause injury and damage.
These “safe distances” ONLY apply to “pneumatic” pressure testing; yet another DISADVANTAGE of this method and a huge ADVANTAGE of the Hydrastatic Method!
Source: ASME PCC-2, Mandatory Appendix 501- 1 1 1 Safe Distance Calculations for Pneumatic Pressure Test