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 mud pump valve including a seat ring having an upwardly facing frusto-conical seating surface and a generally flat closure disc having a downwardly facing frusto-conical seating surface at the lower end thereof. The disc has a groove around the periphere thereof, with the groove having a cross section that includes a flat first side substantially parallel to the plane of the disc, a flat second side at right angles to and extending downwardly from the first side, and a flat third side adjacent and at an angle greater than 90.degree. to the second side. The valve further includes an insert ring contained within the groove having an internal cross section generally congruent to the cross section of the groove except that the width of the first side of the insert is less than the width of the first side of the groove. The insert also includes a fourth side extending outwardly and upwardly at an angle greater than that of the seating surface.