Abstract: A finish for a cylinder liner is provided by first treating the entire inner surface area of the cylinder liner to form a base porosity. An abrasive media is then applied only to portions of the inner surface area to create an extremely light break-in surface, preferably in a pattern such that at any axial location of a piston ring in the cylinder, its periphery is in contact with both the areas of the break-in surface as well as the areas of base porosity to which the break-in surface has not been applied.

Abstract: Disclosed is a mud pump valve which includes a seat ring adapted for insertion in a mud pump. The seat ring includes a frusto-conical seating surface and an annular seal ring groove about its outer periphery. A seal ring is positioned in and bonded to the seal ring groove. The seal ring has a frusto-conical sealing surface having an angle of taper greater than that of the seating surface of the seat ring. A closure disc is reciprocatingly mounted with respect to the seat ring and the closure disc includes a frusto-conical sealing surface having an angle of taper substantially the same as the angle of taper of the seating surface of the seat ring.

Abstract: Disclosed is a single acting mud pump piston assembly adapted for use in a mud pump mechanism including a piston and having an end portion with a shoulder reciprocatingly mounted in a cylinder. The assembly includes a circular flange mounted on the end portion in abuttment with the shoulder. A hub is removably mounted on the end portion in abuttment with the flange. A piston cap is mounted about the hub in abuttment with the flange. The assembly is held together by a washer and a nut engaging the end portion.

Abstract: A finish for a cylinder liner is provided by first treating the entire inner surface area of the cylinder liner to form a base porosity. An abrasive media is then applied only to portions of the inner surface area to create an extremely light break-in surface, preferably in a pattern such that at any axial location of a piston ring in the cylinder, its periphery is in contact with both the areas of the break-in surface as well as the areas of base porosity to which the break-in surface has not been applied.

Abstract: In a pump for pumping fluid having a piston with a flange, a cylinder, a gap between the cylinder and the flange, and a sealing device, an improved sealing device has an anti-extrusion ring located at a face of the sealing device opposite the fluid. The anti-extrusion ring is bonded to the sealing device and is biased to be in intimate, movable contact with the cylinder. The anti-extrusion ring is made from a material having a modulus of elasticity sufficient so that it does not extrude into the gap under the influence of the hydrostatic pressure generated during pump operation. The sealing device, or a portion thereof, has a modulus of elasticity sufficient to control the radially outward expansion of the anti-extrusion ring so that the sides of the ring do not press too tightly against and cause excessive wear of the cylinder. The anti-extrusion ring has at least one split in it, and a ring having a number of tangential-cut splits or step-cut splits could be used.