Abstract This valve control valve comprises a valve body having a central bore therein provided with an intermediate enlarged part and an annular seat, said enlarged part being substantially a first chamber communicated with an inlet in the valve, a valve plug slidably inserted in the bore and having upper and lower cylindrical sliding members, an intermediate brim and a neck portion between the upper sliding member and the brim to define a second chamber there around which is communicated with an out-let of the valve, said brim being positioned in the first chamber and adapted to cooperate with the valve seat to regulate the valve orifice therebetween, and the construction being so arranged that upward and downward fluid pressures within the first chamber to the brim of the plug are balanced and upward and downward fluid pressures in the second chamber to the plug being also balanced thereby moving the plug lightly and easily.
A fluid control valve comprising a valve body having an elongated central bore providing first and second chambers and terminating in a bottom portion, the first chamber having a transverse dimension greater than the transverse dimension of the second chamber, the transverse cross sectional area of the second chamber and the transverse cross sectional area of the bottom portion of the bore being equal, the valve body being provided with a valve seat surrounding the second chamber and separating the second chamber from the first chamber, an elongated valve plug slidably received in the central bore for longitudinal sliding movement therein, the valve plug including a first sliding portion slidably received in and sealingly engaging the bottom portion of the bore, a brim portion extending transversely outwardly from the first sliding portion, the brim portion having an upper surface engageable with the valve seat to seal the first chamber from the second chamber and a lower surface extending outwardly from the first sliding portion, a second sliding portion slidably received in and sealingly engaging the second chamber, and a neck portion extending between the second sliding portion and the brim portion and having a transverse dimension less than the transverse dimension of the second sliding portion, spring means within the bore acting on the valve plug for resiliently biasing thE brim portion of the valve plug against the valve seat, and means on the valve body for moving the valve plug against the bias of the spring means whereby the brim portion is moved away from the valve seat, the portion of the upper surface of the brim portion which extends outwardly of the valve seat when the upper surface engages the valve seat having an area substantially the same as the area of the lower surface of the brim portion, the portion of the upper surface of the brim which is located inwardly of the valve seat having an area substantially the same as the area of the portion of the second sliding portion of the valve plug which extends outwardly of the neck portion whereby neither the pressure within the first chamber nor the pressure within the second chamber exerts a sliding force on the valve plug.
Claim 2
Dependent Claim
369 words
A fluid control valve comprising a valve body having an elongated central bore providing first and second chambers and terminating in a bottom portion, the first chamber having a transverse dimension greater than the transverse dimension of the second chamber, the transverse cross sectional area of the second chamber and the transverse cross sectional area of the bottom portion of the bore being equal, the valve body being provided with a valve seat surrounding the second chamber and separating the second chamber from the first chamber, an elongated valve plug slidably received in the central bore for longitudinal sliding movement therein, the valve plug including a first sliding portion slidably received in and sealingly engaging the bottom portion of the bore, a brim portion extending transversely outwardly from the first sliding portion, the brim portion having an upper surface engageable with the valve seat to seal the first chamber from the second chamber and a lower surface extending outwardly from the first sliding portion, a second sliding portion slidably received in and sealingly engaging the second chamber, and a neck portion extending between the second sliding portion and the brim portion and having a transverse dimension less than the transverse dimension of the second sliding portion, spring means within the bore acting on the valve plug for resiliently biasing thE brim portion of the valve plug against the valve seat, and means on the valve body for moving the valve plug against the bias of the spring means whereby the brim portion is moved away from the valve seat, the portion of the upper surface of the brim portion which extends outwardly of the valve seat when the upper surface engages the valve seat having an area substantially the same as the area of the lower surface of the brim portion, the portion of the upper surface of the brim which is located inwardly of the valve seat having an area substantially the same as the area of the portion of the second sliding portion of the valve plug which extends outwardly of the neck portion whereby neither the pressure within the first chamber nor the pressure within the second chamber exerts a sliding force on the valve plug.