If the brass valve actuator is too small, it will not generate enough torque to operate the brass valve adequately. Generally speaking, we think that the required operating torque of brass valve comes from the friction between the metal parts of brass valve (such as ball core, valve disc) and seal (valve seat). According to the application of the brass valve, use temperature, operating frequency, pipeline and pressure difference, flowing medium (lubrication, drying, mud), many factors affect the operating torque of the brass valve.

The operating torque of the valve is measured continuously from the fully open position to the fully closed position and then back to the fully open position while it is subjected to the static PN 10. During the test the speed of the rotation shall be 5 ± 1 cycles per minute.

The structural principle of the brass ball valve is basically based on a polished ball core (including the channel) sandwiched between two valve seats (upstream and downstream), the rotation of the brass valve ball core intercepts the fluid or flows through the ball core, upstream The force generated by the differential pressure with the downstream causes the ball to rest against the downstream seat (floating brass ball valve structure). In this case, the torque for operating the brass valve is determined by the friction between the ball core and the valve seat, the valve stem and the packing. The torque maximum occurs when a differential pressure occurs and the core rotates in the open direction in the closed position.

The structural principle of the brass gate valve is basically based on the disc fixed on the shaft. In the closed position, the disc and the valve seat are completely sealed. When the disc rotates (around the valve stem) and is parallel to the flow of the fluid, the brass valve is in the fully open position. On the contrary, when the disc is perpendicular to the flow direction of the fluid, the brass valve is in the closed position. The torque of operating the brass gate valve is determined by the friction between the disc and the valve seat, the valve stem and the packing, and the force of the pressure difference acting on the disc also affects the operating torque. Brass valves have the greatest torque when they are closed, and after a small rotation, the torque will decrease significantly.

N10131005 Economical Brass Gate Valve

The structural principle of the brass angle valve is basically based on the plug sealed in the conical plug body. There is a channel in one direction of the stopper of the brass angle valve. The brass valve opens and closes with the plug screwed into the seat. The operating torque is generally not affected by the pressure of the fluid but is determined by the friction between the valve seat and the plug during opening and closing. Brass angle valves have maximum torque when closed. Due to the influence of pressure, the torque remains high for the remainder of the operation.

NAFCO is one of most specialized brass valve manufacturers in China, with over 20 global service experience. Our products cover brass ball valves, brass gate valves, brass check valves, brass angle valves, brass radiator valves, brass fittings and OEM production, sizes from DN8 to DN100, pressures from PN10 to PN40, which widely used for water, gas, oil and heating systems.

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