GATE VALVES are in widespread use for providing a positive control of the flow of fluids through pipe lines, and the like. These valves are normally provided with a gate member which is interposed between the inlet and outlet ports of the valve, and which is reciprocal within the valve body to provide selective open and closed positions therefor. A valve seat is normally provided in the valve body for engagement with the gate member in the closed position of the valve for precluding leakage of fluid. The valve seat is usually disposed on the downstream side of the closure member, and in the closed position of the valve, the pressure of the fluid in the line bears against the closure member for urging the member tightly against the valve seat. Whereas this has been considered a desirable arrangement since the pressure of the fluid may increase the sealing pressure between the gate and the sealing members of the valve seat. However, under actual use conditions, it is frequently very difficult to open the valve since the great forces on the gate member must be overcome in order to raise the gate member from the closed position in the valve body. In order to alleviate this problem, a gate valve as shown in my prior U.S. Pat. No. 3,050,077, issued Aug. 21, 1962, and entitled "Double Sealed Gate Valve" was developed but the construction of this valve is complicated and expensive.
The novel valve comprises a valve body having oppositely disposed inlet and outlet ports providing a fluid passageway therethrough. A gate member or valve closure is interposed between the inlet and outlet ports for intermittently interrupting the flow of fluid therebetween, thus providing alternate open and closed positions for the valve. The gate member may be actuated by either a non-rising or rising valve stem, as is well known. A valve seat is provided conterminous with the inlet port and is provided with suitable sealing means for engagement with the upstream face of the gate member in the closed position thereof. The sealing means provides an efficient sealing of the valve for precluding leakage of fluid around the closed gate member. In addition, the opening of the gate member is greatly enhanced since the fluid pressure on the upstream side of the gate member facilitates the opening thereof. It is also preferable to provide a seal testing means for assuring that the seal means is in an efficient operating condition, thus increasing the environmental efficiency of the valve. The novel Gate Valves is simple and efficient in operation and economical and durable in construction. Cast Gate, Globe, Check Valves

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