An adjustable blowdown safety valve is provided for use on a pressure vessel or a flow line with a pressurized fluid therein. In the preferred embodiment, the adjustable blowdown safety valve comprises a body with a closed bonnet and a chamber therein and an inlet and an outlet; the inlet including a valve seat; a disk member with an attached stem member closable on the valve seat; a mechanism in the body biasing the disk member to rest on the valve seat; a guide member supported in the bonnet to guide and limit disk member movement; and a skirt member affixed to the body, which surrounds the disk member and defines a uniform flow area in combination with a blowdown ring. The presented adjustable blowdown safety valve has improvements, which remove detriments to disk member movement, resulting in an adjustable blowdown safety valve with predictable performance and improved reliability.

A flow regulation valve includes a housing having a valve seat within the housing. A poppet valve disposed in the housing includes a crown and a spring that biases the crown into engagement with the valve seat. An abutment surface is situated to engage an end of the spring distal from the crown. An adjustor that is accessible from outside the housing selectively sets a tension on the spring by moving the abutment surface relative to the crown.

The present disclosure provides a method and apparatus for draining. The apparatus includes a body, the body having a first compartment adjacent to a second compartment, the first compartment having an inlet port fluidly connected to an outlet port, the inlet port defining a needle seat within the first compartment, a first rod hole for operation with a second rod hole in the second compartment, and a plurality of venting holes, the second compartment having a plurality of spaced notches along. The apparatus further includes a setting rod, the setting rod having a shaft and a sealing head, the shaft sized to be slideably maintained in the first rod hole and the second rod hole, the sealing head slideably attached to an end of the shaft and sized to obstruct fluid flow from the inlet port at the needle seat.

A relief valve includes a housing including an internal flow passage through which a working fluid flows, and a relief port discharging the working fluid from the internal flow passage, and a valve body including a first pressure-receiving portion a second pressure-receiving portion receiving pressure with a pressure-receiving area that is larger than a pressure-receiving area of the first pressure-receiving portion, and a first recessed portion formed at the second pressure-receiving portion at an opposite side relative to a pressure-receiving surface of the second pressure-receiving portion and including a closed-end cylindrical shape. The relief valve includes a biasing force adjustment mechanism including a spring of which one end is held at the first recessed portion, a support portion retaining the other end of the spring and including a closed-end cylindrical shape, and a motor adjusting a rotational angle and causing the support portion to reciprocate.

The overload protection device used on a high-speed dental handpiece includes a valve body, a piston, an elastic member, and a valve plug. The valve body is provided with an air chamber and an air intake passage in communication with each other. The piston is arranged in the air chamber. The valve plug is arranged at an end of the air chamber away from the air intake passage and is connected with the valve body. The elastic member is arranged between the piston and the valve plug. An outer surface of the valve body is provided with a plurality of air discharging holes which is in communication with the air chamber. The piston is capable of opening or closing the air discharging holes when moving vertically within the air chamber. The present invention further discloses a high-speed dental handpiece with an overload protection device.

In one aspect, a pressure differential device including: an inlet; an outlet; and a fluid restricting member fluidly associated with the inlet and the outlet, wherein the fluid restricting member is configured to provide a first backpressure at a first setting and a second plurality of backpressures at a plurality of second settings. In another aspect, a method to control backpressure including: providing a fluid line with an inlet fluid flow; supplying the inlet fluid flow into a pressure differential device; expelling an outlet fluid flow out of the pressure differential device; pressurizing the inlet fluid flow to a first backpressure at a first setting of the pressure differential device; pressurizing the inlet fluid flow to a second plurality of backpressures at a plurality of second settings of the pressure differential device.

In one aspect, a pressure differential device including: an inlet; an outlet; and a fluid restricting member fluidly associated with the inlet and the outlet, wherein the fluid restricting member is configured to provide a first backpressure at a first setting and a second plurality of backpressures at a plurality of second settings. In another aspect, a method to control backpressure including: providing a fluid line with an inlet fluid flow; supplying the inlet fluid flow into a pressure differential device; expelling an outlet fluid flow out of the pressure differential device; pressurizing the inlet fluid flow to a first backpressure at a first setting of the pressure differential device; pressurizing the inlet fluid flow to a second plurality of backpressures at a plurality of second settings of the pressure differential device.

A pressure relief valve including a housing having an inlet and a relief outlet connected by a fluid flow passageway, the inlet fluidly connectible to a work string. The pressure relief valve includes a head sealingly disposed within the passageway between the inlet and relief outlet closing the fluid flow passageway between the inlet and relief outlet. An elongate buckling rod supports the head and is bucklable at a predetermined load thereby permitting sliding of the head from between the inlet and a relief outlet and opening the fluid flow passageway. A projection within the housing is extendible to an extended configuration, wherein in the extended configuration the projection applies a lateral force perpendicular to the longitudinal direction of the buckling rod bending the rod from its axial center thereby decreasing the load at which the buckling rod collapses.

A pressure relief valve including a housing having an inlet and a relief outlet connected by a fluid flow passageway, the inlet fluidly connectible to a work string. The pressure relief valve includes a head sealingly disposed within the passageway between the inlet and relief outlet closing the fluid flow passageway between the inlet and relief outlet. An elongate buckling rod supports the head and is bucklable at a predetermined load thereby permitting sliding of the head from between the inlet and a relief outlet and opening the fluid flow passageway. A projection within the housing is extendible to an extended configuration, wherein in the extended configuration the projection applies a lateral force perpendicular to the longitudinal direction of the buckling rod bending the rod from its axial center thereby decreasing the load at which the buckling rod collapses.

A fluid pressure regulating unit, comprises a fluid inlet port, a fluid outlet port, a valve comprising a movable valve part, wherein the movable part comprises at least one fluid pressure balancing means and wherein the at least one pressure balancing means comprises a tapered surface, and a main valve biasing means. The main valve biasing means biases said valve in the direction of an open position. An auxiliary valve biasing means is provided, biasing the valve in the direction of a closed position. Wherein essentially every surface part, being in fluid connection to the fluid inlet port and having a surface normal at least partially in parallel to the moving direction of the moving part of the valve, is balance by a balancing surface part.