A direct acting pressure regulator controls the flow of a gas from a high pressure source to a low pressure device. Gas is delivered from the regulator at a predetermined outlet pressure. The regulator includes a body having a high pressure inlet and defining a seat. A bonnet is engageable with the body to define a piston chamber within the body and the bonnet. The bonnet has a regulated gas outlet. A piston is disposed within the piston chamber and defines a gap between the piston and a wall defining the chamber. The piston is movable between an open regulator condition and a closed regulator condition. The piston includes a plug having a sealing surface engageable with the seat and movable toward the seat to the closed regulator condition and away from the seat to the open regulator condition. The plug includes axially disposed openings therein for communicating gas from around the plug to a central longitudinal bore in the piston. The piston has an impingement surface in flow communication with the central bore such that gas pressure on the impingement surface exerts a force on the piston to move the piston to the closed regulator condition. A spring urges the piston to the open regulator condition.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 10/653,592, filed Sept. 2, 2003, now U.S. Pat. No. 6,851,447.
