초록 ▼

The present invention provides a pressure relief valve having a broad range of variable relief pressures. The valve has an inlet passage, an outlet passage, a valve seat interposed between said passages, a valving member mounted for movement into and out of sealing engagement with the valve seat, a

The present invention provides a pressure relief valve having a broad range of variable relief pressures. The valve has an inlet passage, an outlet passage, a valve seat interposed between said passages, a valving member mounted for movement into and out of sealing engagement with the valve seat, a valve stem assembly operably connected to said valving member, and two or more resilient compression springs of preferably variable length mounted relative to said valve stem to exert a progressively greater compressive force upon said valve stem upon compression of said valve springs, and an adjustable pressure plate assembly for pre-compressing of the compression springs so as to set the relief pressure at a desired pressure value. A preferred embodiment is directed to that comprising a valve stem assembly for preventing the valve spring from being compressed beyond a predetermined selected point of relief pressure. Another preferred embodiment provides a sear assembly which eliminates the possibility of an initial pop-off chattering of the valving member relative to the valve seat. The sear cooperates with the valve base plate to hold the valving member in the sealed position over a pressure span. Once the sear is overcome, valve opening is full. The hysterisis error is thus a desireable value when inspecting a cycle of valve opening and closure.

대표청구항 ▼

An anti-chattering pressure relief valve to provide positive valve opening and closing of the type which includes a main body having a valve seat and valving member, and a bonnet housing a valve stem and spring means extending between a pressure plate and a bottom plate member operably positioned wi

An anti-chattering pressure relief valve to provide positive valve opening and closing of the type which includes a main body having a valve seat and valving member, and a bonnet housing a valve stem and spring means extending between a pressure plate and a bottom plate member operably positioned within the housing bonnet and attached to the valve stem for seating the valving member upon the seat, the invention comprising: sear means independent of the spring means and carried by the housing bonnet for imparting a frictional retention to the base plate member at least prior to opening and prior to closing of the seat by the valving member.