The present disclosure provides an oil scavenge pump, which includes a cap member, a piston member and a resilient member. The cap member and the piston member are connected to each other and with the resilient member therebetween. The cap member includes a cap head, a valve connected to the cap head, a resilient unit disposed between the cap head and the valve, and a first sphere disposed between the resilient unit and the valve. The piston member includes a valve stopper, a main portion, a second sphere, a rod portion, a first-seal ring and a second-seal ring. The main portion has two ends respectively connected to the valve stopper and the rod portion. The second sphere is disposed between the valve stopper and the main portion. The first-seal ring and the second-seal ring respectively surround the main portion and the rod portion.

In a piston including a plurality of piston rings, a state where a difference in differential pressure between the piston rings is eased is maintained even after passage of time, and the life of the piston rings is extended.

A piston includes a piston body in which a plurality of ring grooves is formed, and a plurality of piston rings respectively arranged in the ring grooves. In the piston, a leakage groove is formed on a low-pressure side surface of the ring groove, and in a state where the piston ring is abutted with the low-pressure side surface while being abutted with a cylinder, the leakage groove ensures communication between a high-pressure side space and a low-pressure side space with respect to the piston ring.

A packing arrangement and a method are disclosed, in which a packing assembly of a reciprocating plunger pump is accessible, removable and adjustable from the front end of the fluid-end. As the inside and outside diameter of the packing rings define the area on which the pressure is exerted and results in the total force on the packing arrangement, a packing arrangement with a smaller outside diameter can be advantageous as the forces are reduced and a longer packing life can be expected.

A packing arrangement and a method are disclosed, in which a packing assembly of a reciprocating plunger pump is accessible, removable and adjustable from the front end of the fluid-end. As the inside and outside diameter of the packing rings define the area on which the pressure is exerted and results in the total force on the packing arrangement, a packing arrangement with a smaller outside diameter can be advantageous as the forces are reduced and a longer packing life can be expected.

A long sleeve cartridge for being inserted into a fluid end block of a pump is disclosed. The long sleeve cartridge includes a body and a sleeve bore extending through the body. The sleeve bore includes a first inner diameter and a second inner diameter. The first inner diameter is less than the second inner diameter. A first aperture is located on the body, and a second aperture is located on the body in a radial position substantially diametrically opposite of the first aperture. A packing seal assembly is secured within the long sleeve cartridge. The packing seal assembly includes one or more seals and a biasing mechanism to provide a compression force on the seals. The packing seal assembly is arranged within the second inner diameter when the packing seal assembly is disposed within the long sleeve cartridge.

A long sleeve cartridge for being inserted into a fluid end block of a pump is disclosed. The long sleeve cartridge includes a body and a sleeve bore extending through the body. The sleeve bore includes a first inner diameter and a second inner diameter. The first inner diameter is less than the second inner diameter. A first aperture is located on the body, and a second aperture is located on the body in a radial position substantially diametrically opposite of the first aperture. A packing seal assembly is secured within the long sleeve cartridge. The packing seal assembly includes one or more seals and a biasing mechanism to provide a compression force on the seals. The packing seal assembly is arranged within the second inner diameter when the packing seal assembly is disposed within the long sleeve cartridge.

A piston is described for the compression of a pneumatic fluid in a compression chamber of a cylinder comprising: a cylindrically shaped piston body, adapted to be arranged slidably within said cylinder, and having a side wall and a top wall; along a circumferential perimeter of said side wall of the piston body a seat being defined; and a sealing assembly accommodated in said seat, and adapted to ensure the fluid-tightness along said circumferential perimeter; the sealing assembly comprising a plurality of sealing elements, having shapes complementary to one another, and configured so that the wear of a sealing element along said circumferential perimeter corresponds to a sliding in the radially outer direction of the adjacent sealing element.

A piston is described for the compression of a pneumatic fluid in a compression chamber of a cylinder comprising: a cylindrically shaped piston body, adapted to be arranged slidably within said cylinder, and having a side wall and a top wall; along a circumferential perimeter of said side wall of the piston body a seat being defined; and a sealing assembly accommodated in said seat, and adapted to ensure the fluid-tightness along said circumferential perimeter; the sealing assembly comprising a plurality of sealing elements, having shapes complementary to one another, and configured so that the wear of a sealing element along said circumferential perimeter corresponds to a sliding in the radially outer direction of the adjacent sealing element.

A sealing system for sealing an annulus. The annulus is defined by a cylindrical interior and a cylindrical exterior within, and axially movable relative to, the cylindrical interior. The sealing system includes an inner seal (to surround and sealingly engage the cylindrical exterior), a seal support (to surround, and axially support, the inner seal), an outer seal (to surround the seal support and sealingly engage the seal support and the cylindrical interior), a first support ring (to sit behind an outer periphery of the outer seal), and a back stop (to surround the cylindrical exterior and axially support the seal support and the first ring).

A lubricator package for intermittently delivering a lubricant to lubrication points on packing on a high-pressure reciprocating pump, a frac pump is described. A preferred package includes a large (e.g., 10 gallon) capacity reservoir; a three or five outlet pump; a common manifold receiving oil from the large capacity reservoir and supplying oil or grease to the pumps; a mounting stand supporting the large capacity reservoir and the five outlet pump; and an optional a control package providing low level monitoring of lubricant flow and controlling the pump providing a pump stroke counter or timer.