초록 ▼

An improved valve is provided for blanketing and maintaining the vapor space of a tank with inert gas at a set pressure. The valve is of the type that incorporates a pilot valve that operates in response to sensed tank vapor space gas pressure. The opening and closing of the pilot valve controls the

An improved valve is provided for blanketing and maintaining the vapor space of a tank with inert gas at a set pressure. The valve is of the type that incorporates a pilot valve that operates in response to sensed tank vapor space gas pressure. The opening and closing of the pilot valve controls the opening and closing of an associated main valve which admits pressurized inert gas into the tank from an inert gas supply to maintain the tank set pressure. The valve permits one to externally adjust internal components of the pilot valve after valve assembly. Also, the valve provides for pressure balanced operation that achieves a consistent opening pressure over the allowable range of inlet gas supply pressures.

대표청구항 ▼

In a tank blanketing valve of the type that is associatable with a tank and that incorporates: (a) a housed diaphragm means which moves responsive to the pressure differential between atmospheric pressure and internal tank gas pressure; (b) a pilot valve assembly having a poppet means which longitud

In a tank blanketing valve of the type that is associatable with a tank and that incorporates: (a) a housed diaphragm means which moves responsive to the pressure differential between atmospheric pressure and internal tank gas pressure; (b) a pilot valve assembly having a poppet means which longitudinally reciprocally moves responsively to movements of said diaphragm means; and (c) a main valve assembly having a dome chamber that is associated with said pilot valve assembly and having a reciprocating piston with a normally closed configuration, said piston being associated with said head chamber and said piston being displaced into a predetermined valve open configuration when gas pressure in said head chamber drops below a supply line pressure, thereby to permit passage of pressurized inert gas, whereby, when said poppet means moves to a predetermined valve open position, gas pressure in said head chamber falls below said supply line pressure, and said piston moves to said valve open configuration, and when said poppet means returns to a predetermined valve closed position, gas pressure in said head chamber rises to at least said supply line pressure, and said piston returns to said normally closed configuration, the improvement which comprises a pilot valve assembly comprising: a valve body having a bore defined therethrough, said bore having an upper end and an opposite lower end; two cylindrical plug means in said bore, each one being adjacent a different one of said opposite ends, thereby defining respective upper and lower plug means; screw thread means defined on said lower plug and on said bore for mutually threadable engagement of a circumferential portion of said lower plug means with a lower end adjacent circumferential portion of said bore whereby said lower plug means is selectively longitudinally positionable in said bore; retaining means adjacent said upper end for fixedly positioning said upper plug means in said bore; said upper and said lower plug means in said bore together defining an elongated cylindrical cavity which is discontinuous in a mid-region thereof where opposed respective inner end regions of said upper and said lower plug means are in longitudinally spaced relationship and thereby together define a circumferential medial channel; said upper and said lower plug means defining in cooperate combination with said valve body: (a) a central channel means that interconnects said medial channel with said main valve head chamber, and (b) peripheral channel means that (i) provides a medial circumferential chamber along the outside of each of said upper and said lower plug means and interconnects each of said medical chambers with adjacent portions of said cylindrical cavity, that (ii) interconnects each said medial chamber with the other thereof, and that (iii) interconnects both said medial chambers with a passageway which is defined in said valve body and which is associatable with a tank input gas conduit from said main valve assembly when said valve is associated with said tank; seal means cooperating with said combination for isolating said central channel means from said peripheral channel means when said poppet means is in said valve closed position; said poppet means being elongated and longitudinally slidably positioned in said cylindrical cavity for movement between an upper valve closed position and a lower valve open position, said poppet means having: (a) an upper end and an opposite lower end, and external side walls, (b) an upwardly projecting stem at said upper end that extends through and beyond said upper plug means and that is adapted for engagement with and movement by said diaphragm means, (c) internal conduit means interconnecting a pair of opposite end adjacent portions of said poppet, each one of said opposite end adjacent portions defining with a radially adjacent said plug means a poppet chamber that is radially located in said cylindrical cavity and that is adjacent portions of said poppet side walls, whereby each said poppet chamber communicates with a different one of said medial chambers, and (d) medial circumferentially and radially outwardly extending sidewall regions configured for making sealing engagement between said opposed respective inner end regions of said upper and said lower plug means when said poppet means is in said upper valve closed position, and including sealing means between said medial regions and said respective inner end regions in said upper valve closed position, and spring means and associated spring pin guidance means at said poppet lower end in said lower plug means for yieldingly biasing said poppet in said upper valve closed position, whereby, when said poppet means is in said upper valve closed position, said poppet chambers are each sealed from said medial channel, and, when said poppet means is in said lower valve open position, said poppet chambers communicate with said medial channel so that gas can pass from said head chamber to said passageway.