A method of preventing tampering with a hydrant includes inserting an operating stem of the hydrant through a central bore of an operating nut to mount the operating nut on the operating stem; and rotatably threading a grooved nut onto a threaded distal end of the operating stem, the grooved nut defining an indentation in an outer surface of the grooved nut, wherein: rotatably threading the grooved nut onto the threaded distal end of the operating stem comprises engaging the indentation with a mating groove tool and rotating the grooved nut with the mating groove tool.

A method of preventing tampering with a hydrant includes inserting an operating stem of the hydrant through a central bore of an operating nut to mount the operating nut on the operating stem; and rotatably threading a grooved nut onto a threaded distal end of the operating stem, the grooved nut defining an indentation in an outer surface of the grooved nut, wherein: rotatably threading the grooved nut onto the threaded distal end of the operating stem comprises engaging the indentation with a mating groove tool and rotating the grooved nut with the mating groove tool.

A new system for negative pressure wound therapy is described. The system includes a patient tube set connecting the wound dressing to the suction container. The patient tube set provides separate channels for applying suction to the wound site and sensing the therapeutic pressure at the wound site. A restrictor valve may also be included in order to introduce a small air leak into the system to prevent occlusions in the patient tube set.

An electronic expansion valve comprises: a valve body, the valve body comprising a main body section, an extension section, and a step section, wherein a valve seat core being in a tubular shape and having openings at two ends, wherein the valve seat core comprises a tubular body and a limiting step formed at one end of the tubular body, the tubular body penetrates through the extension section, the limiting step abuts against the inner wall of the step section, and one end of the tubular body away from the limiting step extends out of the extension section; and an air outlet pipe, which is sleeved in the extension section and abuts against an outer wall of the step section, a groove is defined by an inner wall of the air outlet pipe, the extension section, and an outer wall of the tubular body in a surrounding mode.

An actuator assembly includes, a main body, a perimeter compressor, an actuator shaft, an actuator, and a sealing member. The perimeter compressor is slidable between a retracted position and an extended position. The actuator shaft extends through the main body and the perimeter compressor and is operably coupled with a proximal end of the actuator shaft to facilitate movement of the actuator shaft between the extended position and the retracted position. The sealing member includes an inner and outer portion. The inner portion is releasably coupled with the distal end of the actuator shaft and is configured to interface with the valve body. Sliding the perimeter compressor into the extended position facilitates sandwiching of the sealing member between the perimeter compressor and the valve body. Sliding the perimeter compressor into the retracted position facilitates releasement of the sealing member therefrom.

A linear motion mechanism, including a drive portion, a screw shaft which is rotationally driven about an axis by the drive portion and in which a first spiral screw groove is formed on an outer peripheral surface, a nut in which a second spiral screw groove facing the first screw groove is formed on an inner peripheral surface and which moves forward or backward relative to the screw shaft in an axial direction, in which an axis of the screw shaft extends, according to a rotation of the screw shaft, a plurality of load balls which are disposed in a transfer path formed by the first screw groove and the second screw groove and advance while rolling on the transfer path, a plurality of retainer frames which are disposed between the plurality of load balls and advances on the transfer path along with the load balls.

A valve comprises a base, a cover and a sealing member. The base comprises a passage structure and a retaining member; the cover comprises a corresponding retaining member and at least one hole, and the cover is movably combined with the base and switchable between a first state and a second state relative to the base; a sealing member is disposed between the passage structure and the cover. In the first state, the cover closes the passage structure by the sealing member to prevent the flow of the fluid between the cover and the base; in the second state, at least one fluid channel is formed between the cover and the passage structure and is in communication with the at least one hole, and the retaining member and the corresponding retaining member prevent the cover from being separated from the base when the cover moves relative to the base.

Actuator for actuating a valve device comprising an electric drive (14) being operatively engaged to an actuating element (1) of the valve device, the electric drive (14) comprising at least one torque motor (2) which drives a hollow shaft (3) as an internal rotor, that positions a threaded drive (4) having a screw nut (6) and a threaded spindle (5) for converting the rotational movement of the hollow shaft (3) into a translational movement of the threaded spindle (5), and the threaded spindle (5) acts upon the actuating element (1) for displacing the same, wherein the threaded drive (4) comprises an inverted roller screw (4.1), and the screw nut (6) of the inverted roller screw (4.1) houses the threaded spindle (5) as a push rod.

A valve stem lifter assembly which operates to alternatively open and close a valve, includes a rotatably mounted rotary shaft having a free end axially aligned with a pull shaft and an opposite free end axially aligned with an operator for selectively producing rotational movement of the rotary shaft and corresponding axial movement of the pull shaft. The rotary shaft is rotatably connected to a valve riser element by radius set screws positioned axially in the grooves of the rotary shaft. A plurality of guide shaft rods interconnects the riser to the valve stem lifter assembly to prevent axial separation of the riser and rotary shaft while permitting free relative rotation of the rotary shaft and linear movement of the pull shaft.

The present disclosure pertains to a system for controlling a leak flow rate during respiratory therapy. The system is configured to determine a leak flow rate necessary for CO.sub.2 expulsion for an individual subject and facilitate control of the leak flow rate during therapy such that the system exhausts substantially the entire exhaled volume of gas during an expiration of the subject. The system facilitates control of the leak flow rate during therapy via an adjustable leak valve. Determining the leak flow rate for the subject and facilitating control of the leak rate may minimize noise from air flow in the system, minimize the power draw needed by a pressure generator of the system, reduce a loss of medicine added to the respiratory therapy gas, and/or have other advantages, while still expelling the desired amount of CO.sub.2.