... SHINEQUIP offers a complete line of accessories for OEMfluid end modules :Bolts and nuts ,Thread ring ,Upper and ... lower valve Guide ,Liner End Cover ,Valve Pot Cover ,Cylinder Head ,Cylinder Head ... -valve design reduces the volume in the fluid end and improves the volumetric efficiency.When you order parts ... National, Oilwell, OPI, Skytop, Wheatley, and Wilson fluid end Assembly