Indoor / Outdoor Double Acting Actuator , Butterfly Valve Actuator With Hard Sealing

Product Description

Flowan provides the whole set of valve which include pneumatic actuator, valve, limit switch or positioner, solenoid valve, air filter regulator and other related accessories.

For large quantity, it is available to put clients logo on products.

Product Specifications

Actuators are divided into three categories according to their energy forms: pneumatic, electric and hydraulic. They have their own characteristics and are suitable for different occasions. Pneumatic actuators are a category of actuators. Pneumatic actuators can also be divided into two types: single-acting and double-acting: the switching action of the actuator is driven by the air source, which is called DOUBLE ACTING (double-acting). The switch action of SPRING RETURN (single-acting) is only driven by the air source for the opening action, and the spring returns for the closing action.

Note: This article uses DA/SR series pneumatic actuators as an example to explain the selection of actuators. The purpose of this reference is to help customers choose the actuator correctly. Before installing the pneumatic/electric actuator to the valve, the following factors must be considered. * Valve operating torque plus manufacturer’s recommended safety factor/depending on operating conditions. * Air supply pressure or supply voltage to the actuator. * The type of actuator is double-acting or single-acting (spring return) and the output torque under a certain air source or the output torque under the rated voltage. * It is very important to correctly select an actuator for the steering of the actuator and the failure mode (fail open or fail close). If the actuator is too large, the valve stem may be overstressed. Conversely, if the actuator is too small, the side cannot generate enough torque to fully operate the valve. Generally speaking, we think that the torque required to operate the valve comes from the friction between the metal parts of the valve (such as ball core, valve disc) and the seal (valve seat). Depending on where the valve is used, operating temperature, operating frequency, piping and differential pressure, flowing medium (lubrication, drying, mud), many factors affect the operating torque.

The structural principle of the 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 ball center intercepts the fluid or flows through the ball core, the pressure difference between upstream and downstream The resulting force pushes the ball against the downstream seat (floating ball configuration). In this case, the torque to operate the valve is determined by the friction between the ball core and the valve seat, the valve stem and the packing. As shown in Figure 1, the torque maximum occurs when a differential pressure occurs and the core rotates in the closed position in the open direction

Butterfly valve. The structural principle of the butterfly valve is basically based on the butterfly plate fixed on the axis. 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 valve is in the fully open position. On the contrary, when the disc is perpendicular to the flow direction of the fluid, the valve is in the closed position. The torque for operating the butterfly valve is determined by the friction between the disc and the valve seat, the valve stem and the packing. At the same time, the force of the pressure difference acting on the disc also affects the operating torque. For example, when the valve is closed, the torque is the largest, and after a slight rotation, Torque will be significantly reduced

The structural principle of the plug valve is basically based on the plug sealed in the conical plug body. There is a channel in one direction of the stopper. The valve opens and closes with the plug screwed into the valve 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. The valve has maximum torque when it is closed. Due to the influence of pressure, the torque remains high for the remainder of the operation