Replaceable mud pump piston seal
AssigneeNational-Oilwell, L.P.
InventorsMark Alan Staggs, Doug Miller
Life of this patent
Estimating the term…
Abstract
A piston head assembly for reciprocating in a cylinder is disclosed, the cylinder having an inside surface and the inside surface having an inside diameter, comprising: a piston head including a central portion and a flange, the flange having a diameter that is no more than 0.010 inches less than the inside diameter and an annular seal removably mounted on the flange, the seal including a lip and a heel, the lip having an uncompressed diameter that is at least 0.20 inches larger than the inside diameter and the heel being free of a separate retaining means. The seal can also be manufactured so as to be free of any annular depression in its outer surface.
Claims20
A piston head assembly for reciprocating in a cylinder, said cylinder having an inside surface and said inside surface having an inside diameter, comprising:
- a piston head including a central portion and a flange, said flange having a diameter that is no more than 0.010 inches less than said inside diameter when new;
- an annular seal removably mounted on said flange, said seal including a lip and a heel, said lip having an uncompressed diameter that is at least 0.20 inches larger than said inside diameter and said heel being free of a separate reinforcement means.
A method for making a piston head assembly for reciprocating in a cylinder that has an inside surface having an inside diameter, comprising:
- providing a piston head including a central portion and a flange wherein the flange has a diameter that is no more than 0.010 inches less than the inside diameter;
- mounting a removable annular seal on the flange wherein the seal includes a lip and a heel, the lip has an uncompressed diameter that is at least 0.20 inches larger than the inside diameter and the heel is free of a separate retaining means.
A piston head assembly for reciprocating in a cylinder, said cylinder having an inside surface and said inside surface having an inside diameter, comprising:
- a piston head including a central portion and a flange, said flange having a diameter that is no more than 0.010 inches less than said inside diameter;
- a polyurethane annular seal removably mounted on said flange, said seal having a hardness of at least 80 Shore A and including a lip and a heel, said lip having an uncompressed diameter that is at least 0.20 inches larger than said inside diameter and said heel being free of a separate retaining means, wherein said annular seal includes an annular bulge as molded.
Dependencies are inferred from the claim text.