Regulator with erosion resistant seal assemblies

A regulator with erosion resistant seal assemblies, the regulator connected to a pressurized fluid supply, a downstream apparatus and a vent, the regulator comprising:

• a body having a supply port, a regulated port and a vent port, the supply port connected to the pressurized fluid supply, the regulated port connected to the downstream apparatus and the vent port open to atmospheric pressure;
• an axial opening in the body for an elongate control stem;
• a control stem operatively connected to an external adjustment knob to adjust the relative position of the control stem and a sensor piston to adjust a set point of the regulator, the control stem having a closed position in which no fluid flows through the regulator, an open position in which fluid flows from the supply port through the control stem to the regulated port and a vent position in which fluid flows from the regulated port through the control stem to the vent port;
• the control stem having a central shaft with an upper flow passageway proximate a supply seal assembly, and a lower flow passageway proximate a vent seal assembly, the control stem concurrently sealing against the supply seal assembly and the vent seal assembly to prevent fluid flow through the regulator when the control stem is in the closed position;
• the control stem being operatively connected to a sensor piston which is exposed to pressurized fluid in the regulated port to move the control stem when fluid pressure in the regulated port falls below the set pressure to disengage the upper flow passageway from the supply seal assembly to allow fluid to flow from the supply port through the upper flow passageway in the control stem to the regulated port when the control stem is in the open position, the supply seal assembly is further removed from fluid flow with increasing chance in pressure when the control stem is in the open position;
• and
• the control stem being operatively connected to the sensor piston which is exposed to pressurized fluid in the regulated port to move the control stem when fluid pressure in the regulated port exceeds the set pressure to disengage the lower flow passageway from the vent seal assembly to allow fluid to flow from the regulated port through the lower flow passageway in the control stem to the vent port when the control stem is in the vent position, the vent seal assembly is further removed from fluid flow with increasing change in pressure when the control stem is in the vent position.

A flow control regulator with erosion resistant seal assemblies, the regulator comprising:

• a body having a supply port, a regulated port and a vent port;
• an axial opening in the body for movably receiving a control stem therein;
• the control stem operatively connected to a device to adjust a set point of the regulator, the control stem having a closed position in which no fluid flows through the regulator, an open position in which fluid flows from the supply port through the control stem to the regulated port and a vent position in which fluid flows from the regulated port through the control stern to the vent port;
• the control stem having a first portion with an internal first flow passageway with an exterior of the first portion sealingly engaging a supply seal assembly, and having a second portion with an internal second flow passageway with an exterior of the second portion sealingly engaging a vent seal assembly, the control stem concurrently sealing against the supply seal assembly and the vent seal assembly to prevent fluid flow through the regulator when the control stem is in the closed position, said control stem including third and fourth flow passageways forming flow paths between the first flow passageway and the exterior of the control stem;
• the control stem being operatively associated with a sensor member which when exposed to pressurized fluid in the regulated port is operable to move the control stem when fluid pressure in the regulated port falls below the set pressure to connect the supply port to the regulated port through the first flow passageway to allow fluid to flow from the supply port through the first, third and fourth flow passageways in the control stem to the regulated port when the control stem is in the open position while preventing fluid flow past the supply seal assembly;
• and
• the control stem being operatively associated with the sensor piston which when exposed to pressurized fluid in the regulated port being operable to move the control stem when fluid pressure in the regulated port exceeds the set pressure to connect the second flow passageway to the vent port to allow fluid to flow from the regulated port through the second flow passageway in the control stem to the vent port when the control stem is in the vent position.