A packing has an outer circumferential surface and includes a pair of sealing parts located at opposite ends of the packing in a direction along an axis. A piston has a sliding face having a first recess groove. When in the first recess groove, the packing has an outside diameter smaller than the diameter of a slide-receiving face of a cylinder hole. The piston divides the cylinder hole into a pair of chambers. While a compressed fluid is supplied to either one of the chambers, a side edge of the packing adjacent to the chamber at a high pressure is stretched in a radial direction by elastic deformation due to the pressure of the compressed fluid, thus causing a sealing part adjacent to the chamber at the high pressure to reduce a gap formed with the slide-receiving face of the cylinder hole or come into contact with the slide-receiving face.

A packing has an outer circumferential surface and includes a pair of sealing parts located at opposite ends of the packing in a direction along an axis. A piston has a sliding face having a first recess groove. When in the first recess groove, the packing has an outside diameter smaller than the diameter of a slide-receiving face of a cylinder hole. The piston divides the cylinder hole into a pair of chambers. While a compressed fluid is supplied to either one of the chambers, a side edge of the packing adjacent to the chamber at a high pressure is stretched in a radial direction by elastic deformation due to the pressure of the compressed fluid, thus causing a sealing part adjacent to the chamber at the high pressure to reduce a gap formed with the slide-receiving face of the cylinder hole or come into contact with the slide-receiving face.

A screw compressor includes: a screw rotor including a rotor section and a shaft section; a casing having a shaft hole through which the shaft section is inserted, the casing housing the screw rotor; and a delivery side shaft sealing unit configured to seal a clearance between the shaft section and the shaft hole against leakage of a working fluid. The delivery side shaft sealing unit includes an annular groove provided in the shaft section, a seal ring disposed movably in an axial direction of the shaft section within the annular groove, the seal ring being capable of sliding contact with the shaft hole and a side wall surface of the annular groove, and a shaft sealing fluid supply passage communicating with the shaft hole and supplying a fluid to one side, in an axial direction, of the seal ring. The pressure of the fluid that is supplied to the one side, in the axial direction, of the seal ring via the shaft sealing fluid supply passage is set higher than pressure that acts on another side, in the axial direction, of the seal ring. Thus, high shaft sealing performance can be exerted even when the working fluid on the delivery side of the screw rotor has a pressure distribution in a circumferential direction.

A heat exchanger includes a shell. A tubesheet is mounted to the shell. A plurality of tubes extend from the tubesheet and into the shell for heat exchange between a first fluid within the tubes and a second fluid in the shell outside the tubes. The tubesheet divides an interior of the shell into a heat exchange chamber where the tubes can exchange heat with the second fluid, an inlet-outlet chamber for the first fluid to enter and exit the tubes. A breech lock locks the tubesheet within the shell. A bi-directionally self-energizing gasket is seated between the tubesheet and the shell to seal the heat exchange chamber from the inlet-outlet chamber. The gasket is configured to be self-energizing to seal regardless of whether there is a higher pressure in the heat exchange chamber or in the inlet-outlet chamber.

A heat exchanger includes a shell. A tubesheet is mounted to the shell. A plurality of tubes extend from the tubesheet and into the shell for heat exchange between a first fluid within the tubes and a second fluid in the shell outside the tubes. The tubesheet divides an interior of the shell into a heat exchange chamber where the tubes can exchange heat with the second fluid, an inlet-outlet chamber for the first fluid to enter and exit the tubes. A breech lock locks the tubesheet within the shell. A bi-directionally self-energizing gasket is seated between the tubesheet and the shell to seal the heat exchange chamber from the inlet-outlet chamber. The gasket is configured to be self-energizing to seal regardless of whether there is a higher pressure in the heat exchange chamber or in the inlet-outlet chamber.

A high-pressure sealing ring for hydraulic assemblies has a substantiallyL-shaped body with a leg and foot, where an external heel-portion is designed to provide a rolling line of sealing contact with the seat in the cylinder or piston in which it is seated.

A high-pressure sealing ring for hydraulic assemblies has a substantiallyL-shaped body with a leg and foot, where an external heel-portion is designed to provide a rolling line of sealing contact with the seat in the cylinder or piston in which it is seated.

Sealing assemblies with rolling annular seals are provided. In one embodiment, an apparatus includes a stuffing box having a rolling seal positioned in a body for sealing against a tubing or wireline cable received in a bore of the body. The rolling seal can rotate within the body to roll along the tubing or wireline cable in response to movement of the tubing or wireline cable through the body and friction between the rolling seal and the tubing or wireline cable. Additional systems, devices, and methods are also disclosed.

Sealing assemblies with rolling annular seals are provided. In one embodiment, an apparatus includes a stuffing box having a rolling seal positioned in a body for sealing against a tubing or wireline cable received in a bore of the body. The rolling seal can rotate within the body to roll along the tubing or wireline cable in response to movement of the tubing or wireline cable through the body and friction between the rolling seal and the tubing or wireline cable. Additional systems, devices, and methods are also disclosed.

Various embodiments described herein relate to apparatuses and methods associated with fluid pressure sensor systems and sealing members for the same. The sensing apparatus can include a sensor disposed on a substrate and an engagement member including a generally columnar sealing member configured to engage an inner cylindrical surface of a receiving tube within the housing connected to the substrate about the sensor. The sealing member can define an axial bore extending from a proximal end to a distal end, and one or more media can be disposed in the axial bore such that the sensor can detect a force applied to the media. The sealing member can include an outer sealing surface defining one or more engaging elements extending circumferentially about the sealing member, the one or more engaging elements configured to non-adhesively engage the inner cylindrical surface of the receiving tube to resist removal of the sensor assembly.