An electric submersible pump includes a pump, an electric motor that is coupled to the pump by a rotatable shaft, a seal section that is positioned between the pump and the electric motor. The seal section contains an additive and a motor oil for the electric motor. The additive includes one or more superabsorbent polymers or imidate salts to contact the motor oil and to react with a wellbore fluid from a wellbore to prevent premature failure of the electric submersible pump from the wellbore fluid contamination of the motor oil.

A sealing device includes a reinforcing ring having annular shape around an axis line and an elastic body part formed from an elastic body, the elastic body part being attached to the reinforcing ring and having an annular shape around the axis line. The elastic body part includes an annular seal lip and an annular side lip that is provided on an outer side of the seal lip and that extends toward the outer side. In an inner peripheral surface of the side lip on an inner periphery side, at least one circumferential groove which is a groove having an annular shape around the axis line is provided and at least one axial groove which is a groove extending along a direction of the axis line is provided. The circumferential groove and the axial groove are connected with each other.

A sealing device includes a reinforcing ring having annular shape around an axis line and an elastic body part formed from an elastic body, the elastic body part being attached to the reinforcing ring and having an annular shape around the axis line. The elastic body part includes an annular seal lip and an annular side lip that is provided on an outer side of the seal lip and that extends toward the outer side. In an inner peripheral surface of the side lip on an inner periphery side, at least one circumferential groove which is a groove having an annular shape around the axis line is provided and at least one axial groove which is a groove extending along a direction of the axis line is provided. The circumferential groove and the axial groove are connected with each other.

A piston compressor includes a crankcase (11), a crankshaft (12), connecting rods (13), a crosshead (14) with an arranged piston rod (15) and a piston (16), dry-running guided in a cylinder (17). Valves (18) are provided. A piston rod sealing device (19), around the piston rod between the cylinder (17) and the crankcase, includes a gland device (22), arranged in a gland housing (21), inserted into a piston compressor housing (20). The gland device includes a gland jacket (24) pushed into a gland (23) limiting, with the piston rod, a sealing gap (25), which is open over a common longitudinal section, has a width in the .Math.m range and allows a leakage flow (26) of the compressed medium therethrough. The gland and the gland jacket are formed of different materials with a resulting coefficient of thermal expansion essentially the same as the material of the piston rod.

A piston compressor includes a crankcase (11), a crankshaft (12), connecting rods (13), a crosshead (14) with an arranged piston rod (15) and a piston (16), dry-running guided in a cylinder (17). Valves (18) are provided. A piston rod sealing device (19), around the piston rod between the cylinder (17) and the crankcase, includes a gland device (22), arranged in a gland housing (21), inserted into a piston compressor housing (20). The gland device includes a gland jacket (24) pushed into a gland (23) limiting, with the piston rod, a sealing gap (25), which is open over a common longitudinal section, has a width in the .Math.m range and allows a leakage flow (26) of the compressed medium therethrough. The gland and the gland jacket are formed of different materials with a resulting coefficient of thermal expansion essentially the same as the material of the piston rod.

A wellhead annulus packoff and an associated method is disclosed. A retainer lock mechanism of the wellhead annulus packoff is to sit at least partly within a first indentation of a hanger. The retainer lock mechanism includes a bottom surface and a side surface so that the bottom surface is to be associated with a lower energizing ring and the side surface is to be engaged in an energized state with a first side of the seal element. A second side of the seal element is to abut with a surface of a housing and a slot of the seal element is to abut with the lower energizing ring in the energized state of the wellhead annulus packoff.

A valve assembly includes a valve body having a seat-retainer chamber with a floating seat ring disposed adjacent an inner sidewall of the seat-retainer chamber. The floating seat ring is configured to contact a first portion of a plug head at a single annular location prior to a second portion of the plug head contacting a valve primary seat during a closing stroke of the plug head. A static seal is located radially between the floating seat ring and the inner sidewall of the seat-retainer chamber.

A main object of the present invention is to disclose a piston rod sealing unit that solves the problems that have been mentioned from the prior art disclosures. The invention is a piston rod sealing system (0) with a sealing unit (9), for preventing leakage, of gas from a high-pressure chamber (4) to a low-pressure volume (6), and preventing leakage of a lubricant from said low-pressure volume (6) to said high-pressure chamber (4), along a piston rod (1) extending through said chambers (4, 6) said sealing unit (9) comprising, —a deformable gland (10,21,26) arranged for being pressed against said piston rod (1) by one or more compressing elements (15, 22, 27), —a lubricant (F) between the piston rod (1) and the gland (10, 21, 26), said sealing unit (9) arranged between, —a support structure (8) in the low-pressure volume (6) with a plane sliding surface (8a) facing towards said sealing unit (9), —and a wall (7) of said high-pressure chamber (4), —a plane seal (16) constituting a seal between the sealing unit (9) and said wall (7), said plane seal (16) arranged in a groove (13b, 24a, 26e) in said sealing unit (9), said groove open towards said wall (7), or said plane seal (16) arranged in a groove in the wall (7), said groove open towards said sealing unit (9) wherein, —said sealing unit (9) having a surface area towards said wall (7) between said piston rod (1) and said plane seal (16) smaller than the sliding area between said sealing unit (9, 12b, 25a, 28a) and the plane sliding surface (8a), and —said sealing unit (9) being supported by said plane sliding surface (8a) on the low-pressure side, and said sealing unit (9) being in sliding contact with said wall (7) surface (7a), the length (L′) of said sealing unit (9) is less than the length (L) between the base structure (8) and the wall (7) allowing transverse movement of the sealing unit (9) along the sliding surfaces (7a, 8a).

A seal assembly for a hydraulic cylinder piston rod of a hydraulic cylinder includes an annular buffer seal and an annular backup ring. A first axial pressure side of the annular buffer ring faces a rod end chamber of the hydraulic cylinder and fits adjacent a first axial side surface of an annular groove defined in a rod end of the hydraulic cylinder through which the piston rod passes, and a second axial seal side opposite from the first axial pressure side includes a radially outer annular seal surface and a radially inner annular seal surface, wherein the radially outer annular seal surface is spaced farther from the first axial pressure side of the annular buffer seal than the radially inner annular seal surface of the buffer seal such that an annular notch is formed around an inner diameter of the annular buffer seal on the second axial seal side of the annular buffer seal. The annular backup ring includes a radially extending leg portion that extends along substantially an entire radial extent of the radially outer annular seal surface of the annular buffer seal, and an axially extending leg portion that extends axially into the annular notch formed around the inner diameter of the annular buffer seal on the second axial seal side of the annular buffer seal.

A wiping unit for a reciprocating ram includes a subunit including: a ring-shaped wipe member including a lip to press an outer peripheral surface of the ram; and an elastic ring disposed on an outer circumference of the wipe member and configured to press the lip on the outer peripheral surface of the ram. The wipe member is made of rigid resin.