Interstate Pneumatics B312S In Line Blow Gun with Rubber Safety Tip. Interstate Pneumatics Safety Series Blowguns comply with OSHA 1910.242b and 1910.95 by using a tip that reduces the pressure from a maximum of 150 PSI to an outlet pressure of 30 PSI at the nozzle. The tip also includes a safety by-pass which prevents excess pressure build-up in the gun if the nozzle becomes clogged or "dead-ended". All Interstate Pneumatics Safety Series Blowguns have a 1/4 inch NPT female inlet and 1/8 inch NPT female outlet. Area of bottom of blowgun is recessed to perfectly fit the user fingers allowing a firm yet relaxed grip. Application include blowing away dust, metal chips, wood chips etc.