A packing case for a plunger or a piston rod of a reciprocating machine comprises packing cups, each packing cup comprising a body with a hole for the passage of the plunger or rod and a sealing ring seat for housing a sealing ring which slidably bear against the plunger or rod. Packing cups are aligned with each other in series. The packing case comprises lube oil ducts for supplying lube oil from an end of the packing case to the sealing ring seat. Each packing cup comprises sectors, each sector comprising at least lube oil duct portions. The packing cups are positionable to bring, one sector at a time in an activation position where some of the lube oil duct portions of the sector are connected with the lube oil duct portions of an adjacent packing cup to form lube oil ducts. The packing cups are lockable.

Various assemblies that can be used in a mud pump with a plunger-style piston to reduce seal failures, to offer control in variability of the circumference of the piston to thereby control fluid pressure, and to provide visibility into seal condition during operation. In one embodiment, a sleeve that can vary the overall effective circumference of the piston enables fluid pressure control. In some embodiments, seal failure within a pump can be monitored via a drain port that would receive drilling fluid leaking past a seal during operation of the pump. A discharge valve can be provided between an inlet and an outlet of the mud pump to reduce the load on pump components during start-up. Additional systems, devices, and methods are also disclosed.

A stuffing box for sealing a top opening of a vertical pump, including: a housing with a vertical tube for rotatably disposing a shaft of the vertical pump, an annular bearing that: divides the vertical tube in a lower half and an upper half, and fills an annular space between an inner wall of the vertical tube and the shaft, such that as less fluid as possible passes from the lower half through the annular bearing to the upper half, an outlet pipe for discharging the fluid passing through the annular bearing.

Provided is a seal ring configured so that stable lubrication performance can be provided across a wide range of rotation speed. A seal ring for sealing a clearance between a rotary shaft and a housing includes multiple static pressure grooves provided at a sliding surface of the seal ring and arranged in a circumferential direction, the static pressure grooves being opened on a sealed fluid side and closed on an outer diameter side, a circumferential length of each of the static pressure grooves being shorter than a radial length of each of the static pressure grooves.

Provided is a seal ring configured so that stable lubrication performance can be provided across a wide range of rotation speed. A seal ring for sealing a clearance between a rotary shaft and a housing includes; inclined grooves formed at a sliding surface so as to be arranged in a circumferential direction, the inclined grooves being closed on an outer diameter side thereof and configured to generate a dynamic pressure; and supply grooves opening on a sealed fluid side and communicating with an inner diameter side of the inclined grooves.

A seal element for an annular control device includes an elastomer seal sleeve having an annular opening therein and arranged to be radially compressed to contact an exterior of a pipe disposed within the elastomer seal element. The elastomer seal sleeve comprises at least one of a wear resistant material disposed on an interior surface of the annular opening and a lubricant channel on the interior surface.

A sealing device acts to seal a gap between a housing of a gear reducer and a rotational shaft that bi-directionally rotates, and separates an internal space of the housing in which a grease is stored from an atmosphere side. The sealing device includes a main seal lip protruding radially inward from an inner peripheral surface of an inner cylindrical portion. The main seal lip has an internal-side inclined surface disposed on a side of the internal space and an atmosphere-side inclined surface disposed on the atmosphere side. An auxiliary seal lip protrudes radially inward and toward the internal space from the internal-side inclined surface of the main seal lip. Multiple first spiral structures and multiple second spiral structures are formed on at least one of the atmosphere-side inclined surface of the main seal lip and an inner peripheral surface of the auxiliary seal lip.

The present invention relates to a stuffing box assembly comprising a stuffing box and a solid plate, the solid plate may be placed at the shaft introducing end of the stuffing box, between the stuffing box and a surface, when the stuffing box assembly is mounted on to the surface, the solid plate may be on a first side provided with a pressure plate flange and on a second side be provided with a counter pressure plate flange, wherein the pressure plate flange and/or the counter pressure plate flange is provided with one or more locking projections pointing towards the solid plate.

A stuffing box for sealing a top opening of a vertical pump, including: a housing with a vertical tube for rotatably disposing a shaft of the vertical pump, an annular bearing that: divides the vertical tube in a lower half and an upper half, and fills an annular space between an inner wall of the vertical tube and the shaft, such that as less fluid as possible passes from the lower half through the annular bearing to the upper half, an outlet pipe for discharging the fluid passing through the annular bearing.

A mechanical seal device for a centrifugal separator includes a first seal ring including a first seal surface and a second seal ring including a second seal surface. The first and second seal surfaces are configured to face each other to form a seal, and at least one channel for a cooling fluid is arranged in the first seal ring. The at least one channel includes an inlet and an outlet. The outlet of the at least one channel is arranged at the first seal surface of the first seal ring. A centrifugal separator includes the mechanical seal device.