There are five general body styles of ball Valves: single body, three-piece body, split body, top entry, and welded. The difference is based on how the pieces of the valve-especially the casing that contains the ball itself-are manufactured and assembled. The valve operation is the same in each case. Stainless Steel Ball Valves, Brass Ball Valves, Sanitary Ball Valves, Water Ball Valves ZHEJIANG KINGSIR VALVE CO., LTD. , https://www.kingsirvalve.com
A step-down starter that reduces the starting current by pulling out one or several taps from an autotransformer to reduce the terminal voltage at the start of the induction motor. Due to the use of auto-transformer multi-tap decompression, this starter can adapt to the needs of different load starting. The reduced voltage is less than that of the star-delta starter, and a larger starting torque than the star-delta starter can be obtained. In addition, because of the installation of thermal relays and loss of pressure release, auto-coupling decompression starter also has overload protection and loss of pressure protection, often used to start a larger capacity squirrel-cage asynchronous motor.
In addition, there are different styles related to the bore of the ball mechanism itself.
Ball valves in sizes up to 2 inch generally come in single piece, two or three piece designs. One piece ball valves are almost always reduced bore, are relatively inexpensive and generally are throw-away. Two piece ball valves are generally slightly reduced (or standard) bore, they can be either throw-away or repairable. The 3 piece design allows for the center part of the valve containing the ball, stem & seats to be easily removed from the pipeline. This facilitates efficient cleaning of deposited sediments, replacement of seats and gland packings, polishing out of small scratches on the ball, all this without removing the pipes from the valve body. The design concept of a three piece valve is for it to be repairable.
Explosion-proof self-coupling decompression starting box working principle
Self-coupling decompression starters are available both manually and automatically. The manual auto-coupling decompression starter consists of a box, an autotransformer, a contact system, a protection system, and an operating mechanism. The operating handle has three positions, the middle is a "stop" position; the inward push is a "start" position; the outward pull is a "running" position. In order to ensure that the motor must be stepped down to start full-pressure operation, a mechanical interlock is also set in the operating mechanism. Automatic auto decompression starter consists of box, knife switch, fuse, button, AC contactor, thermal relay, time relay and autotransformer. It is through the time relay and AC contactor to achieve the automatic conversion from step-down starting to full-pressure operation. Automatic auto-coupling decompression starter is generally used to control the starting process of a larger capacity motor.
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