A control system having a first pressure regulator, a downstream fluid control device, first pilot, and second pilot. The first pressure regulator has a fluid inlet, fluid outlet, and actuator assembly with a cavity divided into a first chamber and a second chamber. The downstream fluid control device has a second fluid inlet and a second fluid outlet. The first pilot has a first setpoint and the second pilot has a second setpoint, less than the first setpoint. The first and second pilots fluidly couple the second chamber to the second fluid outlet in a first mode of operation, isolate the second chamber from the second fluid outlet in a second mode of operation, and fluidly couple the second chamber to the fluid inlet in a third mode of operation.

A control system having a first pressure regulator, a downstream fluid control device, first pilot, and second pilot. The first pressure regulator has a fluid inlet, fluid outlet, and actuator assembly with a cavity divided into a first chamber and a second chamber. The downstream fluid control device has a second fluid inlet and a second fluid outlet. The first pilot has a first setpoint and the second pilot has a second setpoint, less than the first setpoint. The first and second pilots fluidly couple the second chamber to the second fluid outlet in a first mode of operation, isolate the second chamber from the second fluid outlet in a second mode of operation, and fluidly couple the second chamber to the fluid inlet in a third mode of operation.

A handheld combustion powered fastening tool may include a driving system that drives fasteners into workpieces in response to combustion of fuel by the driving system. A fuel delivery system may supply fuel to the driving system. The fuel delivery system may include a fuel canister storing liquid fuel, such as liquid hydrocarbons such as propane, and a fuel metering valve supplying a previously set amount, or volume, of fuel from the fuel canister to the driving system for combustion.

A handheld combustion powered fastening tool may include a driving system that drives fasteners into workpieces in response to combustion of fuel by the driving system. A fuel delivery system may supply fuel to the driving system. The fuel delivery system may include a fuel canister storing liquid fuel, such as liquid hydrocarbons such as propane, and a fuel metering valve supplying a previously set amount, or volume, of fuel from the fuel canister to the driving system for combustion.

A fluid-flow control device includes a valve aperture and a mounting member arranged downstream of the aperture. A valve member, movably mounted on the mounting member, controls the flow of fluid through the aperture. A control volume, defined between the mounting member and the valve member receives a control fluid from a control fluid feed. A variable flow restrictor is rotatably arranged within a restriction volume of the control fluid feed such that a flow path connecting the inlet, and the outlet, of the restriction volume is defined between the restrictor and the wall of the restriction volume. The restrictor is axi-symmetric about its axis of rotation.

A spring-operated relief valve can include an adjustable main spring to bias the valve closed and a load cell that is configured to measure a force exerted by the main spring. Measurements from the load cell can be used to determine a set or crack pressure in the spring-operated relief valve, and to monitor operation of the spring-operated relief valve.

An improved unloader valve assembly for a high-speed reciprocating compressor includes improved poppets and valve seat designs. The improved poppets and valve seats are useful for reducing or eliminating poppet leakage and high impact stresses on the sealing surfaces of the poppets, and are especially intended for use with high-speed reciprocating compressors operating at 1000 rpm and higher. A control chamber spacer plate for creating a control pressure chamber within the unloader valve assembly, and a valve seat cushioning plate for reducing stress on the head ends of the poppets are also described.

An improved unloader valve assembly for a high-speed reciprocating compressor includes improved poppets and valve seat designs. The improved poppets and valve seats are useful for reducing or eliminating poppet leakage and high impact stresses on the sealing surfaces of the poppets, and are especially intended for use with high-speed reciprocating compressors operating at 1000 rpm and higher. A control chamber spacer plate for creating a control pressure chamber within the unloader valve assembly, and a valve seat cushioning plate for reducing stress on the head ends of the poppets are also described.

The device includes a main valve, first and second auxiliary valves, a valve body and a filter. The main, which has first and second auxiliary valves are mounted on the valve body, which has an air inlet, a cylinder port and an air discharging port. The air inlet is in communication with the main valve through a first air passage, the cylinder port is sequentially in communication with the first and second auxiliary valves, and the main valve through a second air passage. The air discharging port is sequentially in communication with the first and second auxiliary valves and the main valve through a third air passage. The main and the second auxiliary valves are solenoid valves, and the first auxiliary valve is a hand-operated valve. An air outlet of the filter is in communication with the air inlet. The filter is used for filtering out impurities in gas.

The device includes a main valve, first and second auxiliary valves, a valve body and a filter. The main, which has first and second auxiliary valves are mounted on the valve body, which has an air inlet, a cylinder port and an air discharging port. The air inlet is in communication with the main valve through a first air passage, the cylinder port is sequentially in communication with the first and second auxiliary valves, and the main valve through a second air passage. The air discharging port is sequentially in communication with the first and second auxiliary valves and the main valve through a third air passage. The main and the second auxiliary valves are solenoid valves, and the first auxiliary valve is a hand-operated valve. An air outlet of the filter is in communication with the air inlet. The filter is used for filtering out impurities in gas.