摘要 |
A low gas pressure emergency shutdown valve forms part of a valve body having a flow passageway interposed in a gas supply line and forming a gas pressure regulator having a diaphragm/spring responsive poppet valve and a companion diaphragm responsive shutoff valve in the upstream end portion of the valve body maintained open by a pin bearing against the shutoff valve stem. Downstream fluid pressure, in response to a predetermined pressure limit in a flow control chamber, biases the diaphragm in a pin collapsing direction and moves the shutoff valve to a flow passageway closed position. |