Slide flow distributor (100) comprising a motor (1) moving directly a spool (2) by means of a rod (8) of the motor, a charge chamber (3) of the working fluid, in central position, in fluid communication with two discharge branches (4, 5) and two delivery branches (6, 7) and characterized in that from the portion of the spool (2) proximal to the motor (I) it is provided a pneumatic servo-actuator (9) generating a force in the same direction and development of the axial force of the motor (I), with the result that the spool (2) is accelerated in a predetermined direction, said pneumatic servo-actuator comprising a profiled body (52), a plurality of balls (50) and corresponding elastic means (5 1) which press said plurality of balls (50) on the side surface of the profiled body (52).

A normally closed subplate mounted valve has a lower valve seat defining a function port, an upper seat, and a sleeve between the upper seat and the lower seat. The sleeve defines a first port. The poppet is movable within the sleeve to selectively seal against the lower seat in a piloted position or to seal against the upper seat in an offset position. The poppet blocks the first port when the poppet is positioned in an offset position. A piston shaft is affixed to the poppet for moving the poppet into the piloted or offset position. A spring biases the poppet in the offset position for preventing fluid flow into the first port. A pilot port supplies pressure for sliding the piston to compress the spring and to move the poppet away from the offset position to the piloted position so that fluid may flow into a supply port and out of the function port. A second port may be provided in the sleeve. The ports may be selectively configured for supply or vent. Components may be joined with retainer springs. The piston shaft and poppet connector may be a key and key slot engagement. The ports may be shaped for progressive exposure by movement of the poppet. The poppet may be designed to enable pressure assist through the first port when moving the poppet to the piloted position. The valve seats may be provided with angled sealing surfaces that are angularly offset from their mating counterparts.

A normally closed subplate mounted valve has a lower valve seat defining a function port, an upper seat, and a sleeve between the upper seat and the lower seat. The sleeve defines a first port. The poppet is movable within the sleeve to selectively seal against the lower seat in a piloted position or to seal against the upper seat in an offset position. The poppet blocks the first port when the poppet is positioned in an offset position. A piston shaft is affixed to the poppet for moving the poppet into the piloted or offset position. A spring biases the poppet in the offset position for preventing fluid flow into the first port. A pilot port supplies pressure for sliding the piston to compress the spring and to move the poppet away from the offset position to the piloted position so that fluid may flow into a supply port and out of the function port. A second port may be provided in the sleeve. The ports may be selectively configured for supply or vent. Components may be joined with retainer springs. The piston shaft and poppet connector may be a key and key slot engagement. The ports may be shaped for progressive exposure by movement of the poppet. The poppet may be designed to enable pressure assist through the first port when moving the poppet to the piloted position. The valve seats may be provided with angled sealing surfaces that are angularly offset from their mating counterparts.

A normally closed subplate mounted valve has a lower valve seat defining a function port, an upper seat, and a sleeve between the upper seat and the lower seat. The sleeve defines a first port. The poppet is movable within the sleeve to selectively seal against the lower seat in a piloted position or to seal against the upper seat in an offset position. The poppet blocks the first port when the poppet is positioned in an offset position. A piston shaft is affixed to the poppet for moving the poppet into the piloted or offset position. A spring biases the poppet in the offset position for preventing fluid flow into the first port. A pilot port supplies pressure for sliding the piston to compress the spring and to move the poppet away from the offset position to the piloted position so that fluid may flow into a supply port and out of the function port. A second port may be provided in the sleeve. The ports may be selectively configured for supply or vent. Components may be joined with retainer springs. The piston shaft and poppet connector may be a key and key slot engagement. The ports may be shaped for progressive exposure by movement of the poppet. The poppet may be designed to enable pressure assist through the first port when moving the poppet to the piloted position. The valve seats may be provided with angled sealing surfaces that are angularly offset from their mating counterparts.

A fluid pressure controlled spool valve minimizes abrasion or sticking caused by a tilted orientation of a pressure plate forcing lands of a spool shaft to abrade or stick internally facing surfaces of a cylindrical barrel supporting the spool shaft. A permanent magnet is mounted on the pressure plate. A round head composed of a ferromagnetic material is formed on an end of a spool shaft and configured to be magnetically attracted to the permanent magnet. A magnetic attraction force vector produced on the round head of the spool shaft remains coaxial with an axis of the spool shaft, when the pressure plate and the magnet are tilted with respect to the axis of the spool shaft.

A fluid pressure controlled spool valve minimizes abrasion or sticking caused by a tilted orientation of a pressure plate forcing lands of a spool shaft to abrade or stick internally facing surfaces of a cylindrical barrel supporting the spool shaft. A permanent magnet is mounted on the pressure plate. A round head composed of a ferromagnetic material is formed on an end of a spool shaft and configured to be magnetically attracted to the permanent magnet. A magnetic attraction force vector produced on the round head of the spool shaft remains coaxial with an axis of the spool shaft, when the pressure plate and the magnet are tilted with respect to the axis of the spool shaft.

A trip system for a steam turbine closes a trip-and-throttle valve and a control valve of a steam turbine in an emergency. The trip system includes: an emergency shut-off device that shuts off supply of control oil for the trip-and-throttle valve and the control valve to close the trip-and-throttle valve and the control valve; and a drain device that includes a plurality of solenoid valves connected in parallel and drains the control oil by opening the solenoid valves. The emergency shut-off device includes a cylinder, a piston that slides in the cylinder, a spring that applies biasing force to the piston, a plurality of piston valves provided to the piston, and a plurality of chambers formed by the piston valves.

A slide flow distributor to direct and modulate a gaseous fluid, in inlet and outlet. This regulation is carried out by means of a spool, which conveys compressed air in a determined charging direction and puts in communication the other chamber with the environment at the same time. This is a servo-actuator which can be used in the field of pneumatic systems of valve actuation. It has a specific pneumatic servo-actuating system using compressed air. This distributor uses a linear motor using a new pneumatic servo-actuator which generates a force in the same direction of the axial force of the motor, with the result that the spool is accelerated in a predetermined direction. The pneumatic servo-actuator is made of a profiled body, a plurality of balls and corresponding elastic means which press the plurality of balls on the side surface of the profiled body.

Upper and/or lower seal plates of a sub plate mounted, pilot actuated spool valve are reinforced with one or more metal rings. In a number of preferred embodiments, the metal ring is comprised of steel. Portions of the seal plates may comprise an engineering thermoplastic such as polyoxymethylene (POM) sold by E. I. DuPont de Nemours under the DELRIN trademark. The plastic material may be molded to the metal ring. In other embodiments, the plastic material and metal ring(s) are mechanically connected together.

Upper and/or lower seal plates of a sub plate mounted, pilot actuated spool valve are reinforced with one or more metal rings. In a number of preferred embodiments, the metal ring is comprised of steel. Portions of the seal plates may comprise an engineering thermoplastic such as polyoxymethylene (POM) sold by E. I. DuPont de Nemours under the DELRIN trademark. The plastic material may be molded to the metal ring. In other embodiments, the plastic material and metal ring(s) are mechanically connected together.