Abstract: A header and a pump end for a cryogenic pump are provided for efficient liquid pumping operation. The header directs supplied liquid into a sump and gas into a freeboard. The liquid in the header can be distributed along the header and decanted over a weir to the sump, the liquid being drawn from the sump and up through the vessel to the pump end. Gas in the freeboard is collected for venting or return to the liquid source. Pump head plunger stroke can be lengthened and operated at slower stroke rates using a large cross-sectional area intake and discharge valves. Plunger seals, supported as a seal pack in a sleeve, are field installable over the plunger. A plunger to drive shim arrangement permits filed adjustment of the stroke.

Abstract: A pump for pumping fluid down a well bore in a rock formation comprises: intake and discharge passages; a pumping chamber with a plunger therein; intake and discharge valve assemblies in the intake passage and the discharge passages. At least one valve assembly has a valve body movable into sealing contact with the valve seat by fluid pressure in the pumping chamber. The valve seat may have a cylindrical outer surface for mating reception in said intake passage, and a shoulder with a radially-projecting surface biased against a wall for sealing. A cushioning member may be interposed between the valve body and the valve seat. A seal may be interposed between said valve body and said valve seat, and configured so that between 35% and 60% of a sealing surface of said valve seat contacts the valve body.