Hydraulically controlled water spool valve

摘要

A valve, to control the injection of lubricant into a viscous material pump pipeline is disclosed. The valve is operated off a parameter of the viscous material pump such as hydraulic fluid pressure from one or both differential/popper teed lines for the pump. The preferred valve includes coaxial water and hydraulic oil spools on opposing ends of a rod, and two hydraulic signals are used to control water flow through two outlets, to properly feed water to two lubricant injectors. Inlets and outlets of the valve are all located along one surface, and an intermediate chamber is provided to receive any leakage past the rod seals.