Analog simulation of a gas pressure regulator.

The behavior characteristics of direct-acting gas pressure regulators are discussed in terms of spring force, flow force, and friction force. The dynamics of the metering valve and bellows assembly are described by equating all forces on the valve to zero. Continuity equations for the regulator are derived. Simulations are carried out to determine effects of sensing orifice diameter, poppet stem friction, output volume, and supply pressure on regulator behavior. Several regulator configurations are studied.