A multistage stacked disk choke includes a housing having a high pressure inlet port and a low pressure outlet port, an assembly, a cage, a seat, and a plug. The assembly includes: a tubular inlet port, a galley intersecting the tubular inlet port, a tubular outlet port, and a bore inward from the tubular outlet port. The cage has an inlet port in communication with the tubular inlet port. The seat is configured to support the assembly. The plug moves inside the assembly bore and restricts flow through the tubular outlet port and/or the tubular inlet port. Operation fluid flows from the high pressure inlet port through the cage inlet port into the tubular inlet port and is redirected into the galley and into the tubular outlet port into the bore of the assembly to a bore in the seat, and out through the low pressure outlet port.

A check valve including a valve housing defining a pair of valve openings; a pair of flappers pivotably mounted for rotation relative to the housing between an open position in which they permit fluid flow through the respective valve openings and a closed position in which they prevent fluid flow through the valve openings; and a stop element arranged such that the flappers will contact the stop element in their open positions. Each flapper includes a primary flapper element pivotally mounted to a hinge pin that extends across the valve, and a secondary flapper element. The primary flapper element further includes at least one flapper opening formed therethrough. The secondary flapper element is pivotally mounted such that it may rotate relative to the primary flapper element for opening and closing the at least one flapper opening in the primary flapper element.

According to some embodiments of the invention, an adjusting device for adjusting a passive drip irrigation valve to enable precision irrigation includes a device body configured to be at least one of hand-held or attachable to a robot, the device body having a manipulator end, and a manipulator assembly contained within and extending from the manipulator end of the device body. The manipulator assembly includes a coarse alignment adjustment assembly constructed and arranged to align the adjusting device with the passive drip irrigation valve. The manipulator assembly also includes a fine actuator configured to rotate the passive drip irrigation valve by a specified angle.

A solenoid-operated valve assembly that reduces the jet flow of fluid or gas in an axially exiting valve. The valve assembly comprises a spool valve, a valve member housing, and a flow path. The spool valve comprises a fluid communication channel, a tail, and an inlet seat. The valve member housing comprises at least one inlet, at least one nozzle flow director, and at least one outlet. The flow path begins at the at least one inlet and exits at the at least one outlet. The at least one nozzle flow director is within the flow path. The spool valve moves axially within the valve member housing between a closed position and an open position. The inlet seat closes the at least one flow path at the inlet when the spool valve is in the closed position. A method of operation of the solenoid-operated valve assembly is also provided.

A control valve is provided for a fluid treatment apparatus, including a housing with at least one cylinder defining a fluid flow path in the apparatus, each cylinder having an associated reciprocating piston valve. The valve includes a first piston valve half; a second piston valve half complementary to the first piston valve half; and a resilient seal constructed and arranged for being sandwiched between the first and second piston valve halves. The first piston valve half is constructed and arranged for engaging the cylinder before the second piston valve half, and having an exterior peripheral edge defined by a plurality of peripherally spaced teeth creating flow spaces between the teeth.

A control valve is provided for a fluid treatment apparatus, including a housing with at least one cylinder defining a fluid flow path in the apparatus, each cylinder having an associated reciprocating piston valve. The valve includes a first piston valve half; a second piston valve half complementary to the first piston valve half; and a resilient seal constructed and arranged for being sandwiched between the first and second piston valve halves. The first piston valve half is constructed and arranged for engaging the cylinder before the second piston valve half, and having an exterior peripheral edge defined by a plurality of peripherally spaced teeth creating flow spaces between the teeth.

A chemical injection valve can include a valve stem reciprocably disposed relative to a primary seal, and a variable flow restrictor upstream of the primary seal relative to a direction of flow through the chemical injection valve. The variable flow restrictor restricts the flow when the valve stem is disengaged from the primary seal. A chemical injection system can include a chemical treatment pumped through a chemical injection valve and into an interior of a tubular string in a well, the chemical injection valve including a valve stem, a primary seal sealingly engaged with the valve stem in a closed position and disengaged from the valve stem in an open position, and a flow restrictor that restricts the flow of the chemical treatment downstream from the primary seal in the open position.

A chemical injection valve can include a valve stem reciprocably disposed relative to a primary seal, and a variable flow restrictor upstream of the primary seal relative to a direction of flow through the chemical injection valve. The variable flow restrictor restricts the flow when the valve stem is disengaged from the primary seal. A chemical injection system can include a chemical treatment pumped through a chemical injection valve and into an interior of a tubular string in a well, the chemical injection valve including a valve stem, a primary seal sealingly engaged with the valve stem in a closed position and disengaged from the valve stem in an open position, and a flow restrictor that restricts the flow of the chemical treatment downstream from the primary seal in the open position.

A snap-action valve assembly for an exhaust system and a method for manufacturing the same is provided. The valve assembly includes a first conduit and a second conduit that is partially received in the first conduit. A valve flap is disposed within the first conduit for controlling exhaust flow. A shaft supports the valve flap in the first conduit for rotation between open and closed positions. The first conduit has first and second slots, each extending from an open slot end to a closed slot end. First and second bushings supporting the shaft are disposed within the slots between the second conduit and the closed slot ends. A pad made of wire mesh is attached to the valve flap. The pad includes an end portion that contacts the first conduit in the closed position to dampen vibration and reduce valve flap flutter.

A snap-action valve assembly for an exhaust system and a method for manufacturing the same is provided. The valve assembly includes a first conduit and a second conduit that is partially received in the first conduit. A valve flap is disposed within the first conduit for controlling exhaust flow. A shaft supports the valve flap in the first conduit for rotation between open and closed positions. The first conduit has first and second slots, each extending from an open slot end to a closed slot end. First and second bushings supporting the shaft are disposed within the slots between the second conduit and the closed slot ends. A pad made of wire mesh is attached to the valve flap. The pad includes an end portion that contacts the first conduit in the closed position to dampen vibration and reduce valve flap flutter.