Patent ID: 7513270
Filing Date: 2009-04-07
Classification: F16K,Y10T

Abstract:
1. A balanced safety relief valve comprising: a body formed with an interior chamber; a flow inlet arranged to extend through one end of said body for flow communication with one end of said chamber and having an inner end bounded by a valve seat in flow outlet communicating with said one end of said chamber peripherally of said valve seat; a guide opening disposed in alignment with said flow inlet and opening into an opposite end of said chamber through an opposite end of said body; an elongated spindle means aligned with said flow inlet and having one end arranged to removably engage with said valve seat for removably preventing passage of fluid from said flow inlet into said chamber, an opposite end arranged to extend through said guide opening, and an enlarged mid-portion for dividing said chamber into said one and said opposite ends, means for biasing said one end of said spindle into engagement with said valve seat for removably blocking flow of fluid into said chamber from said flow inlet, said biasing means tending to establish a set point at which said spindle means will disengage from said valve seat and permit flow of fluid from said inlet into said chamber for discharge through said outlet; means establishing a fluid flow path placing said outlet in flow communication with said opposite end of said chamber for establishing a force acting on said opposite end of said spindle means equal and opposite to a force exerted on said one end of said spindle means due to pressure with said outlet, whereby to balance said valve and prevent the changes in pressure in said outlet from effecting changes in said set point; and a fluid seal engaging with said body and said spindle means, for preventing passage of fluid from said opposite end of said chamber outwardly of said body through said guide opening; wherein said spindle means include a first part defining said one end and said mid-portion of said spindle means, and a spindle cap fixed to said mid-portion and cooperating therewith to locate said fluid seal lengthwise of said spindle means within said guide opening.