Fluid end for a plunger pump

Claim 1

In a plunger pump, an improved fluid end construction comprising: a cylinder body having a plunger bore formed therein; a plunger mounted in said bore and adapted to reciprocably move therein; a crossbore body having suction and discharge flow passages formed therein, the diameter of each of said flow passages being substantially smaller than the diameter of said plunge plunger; first coupling means for joining said cylinder body and said crossbore body wherein said flow passages are in fluid communication with said plunger bore; a suction valve cage containing a part at least of a suction valve; second coupling means for joining said crossbore body and said suction valve cage wherein said suction flow passage is in fluid communication with said suction valve; a discharge valve cage containing a part at least of a discharge valve; and third coupling means for joining said crossbore body and said discharge valve cage wherein said discharge flow passage is in fluid communication with said discharge valve, each of said coupling means including a segmented collar adapted to clamp together the members being joined, and a self-energizing seal ring engaging internal surfaces of each member being joined, the engagement of said seal ring on said surfaces being such that the fluid pressure internally of said seal ring tends to increase the engagement pressure.