Orifice device with safety shut-off for pressure regulators

A pressure regulator operative in responsive to inlet pressure and outlet pressure comprising;

• a. a housing having an inlet, an outlet, a transverse wall therebetween, and a chamber formed on the outlet side,
• b. an orifice device connected in the transverse wall and including a shut-off valve on the inlet side and a valve seat on the outlet side,
• c. a flexible diaphragm having one side in communication with the outlet connected in the chamber,
• d. a diaphragm valve element operatively actuated by the diaphragm to be shifted a predetermined distance toward and away from the valve seat responsive to the pressure in the chamber, and
• e. the valve element, during normal operation of the pressure regulator, to engage and to hold open the shut-off valve whereby upon under pressure in the outlet chamber or excessive flow through the orifice device causes the shutoff valve to be actuated to close the orifice device and to prevent any flow therethrough,
• the orifice device including a body having a passage therethrough and the valve seat formed on the outlet side thereof,
• the shut-off valve including the body having a valve seat formed on the inlet side thereof, a valve stem located within said passage and having a valve head coacting with the valve seat and a tension spring located within said passage and surrounding a portion of the length of the stem to interconnect the valve stem to the body, and the valve stem extending from the passage in the body to be engaged by the diaphragm valve element whereby the shut-off valve is held open during normal operation of the pressure regulator, and will be biased closed by the force of the spring and locked down by the force exerted by the inlet pressure to prevent any flow through the orifice device upon under pressure in the outlet chamber or excessive flow through the orifice.
• said passage being counterbored with the smaller diameter portion adjacent the diaphram valve seat
• said spring is a coil spring having one end connected to the valve stem adjacent said valve head and the other end secured to the small diameter portion whereby the spring will normally be placed in tension by the force of the diaphram valve element shifting the valve stem to hold the shut-off valve open.