... to each other easily and reliably. Fluid End (cylinders, valve assembly, liners and pistons) Cylinders are made of forged alloy ... steel, three cylinders of each pump are interchangeable. Valve-over-valve (through type cylinder)design reduces the cylinder volume ... sealing.Notes: Cylinders, liners, pistons, valves, valve seats, valve springs, seal rings, valve covers and cylinder covers at the fluid end ...