Electrically Controlled Valves.

Automatic electrically controlled valve operators arc of two general types, electric-solenoid (or magnetic) and electric motor. Technical Data used in the field explained in diploma in petroleum engineering.

Magnetic operators are used for valves requiring longitudinal motion to position the inner valve. The use of magnetic operators generally is limited to valves 2 in. and smaller in size and of relatively low working pressures. Electric-motor operators can be used with any type of valve but in all cases must include accessories that provide a torque-limiting means and a limit switch to prevent damaging the motor when either extreme valve position is reached. On valves requiring longitudinal motion to seat the inner valve electric-motor, operators also must include a gear rack and pinion to co invert the motor’s rotary motion to longitudinal displacement. Because of the relative expense of electric-motor operators, they normally are used only on large-sized valves and/or valves having high working pressures.

Fluid-Electric Controlled Valves. Self-contained valve operators in the third category are  generally hydroelectric-type operators. Operators of this type essentially consist of a self-contained reservoir of hydraulic fluid, a small electric motor, a pump, and a fluid-cylinder device-all within a single housing. The fluid-cylinder principle limits this type of operator to valves requiring longitudinal motion or 90” rotation to seat the inner valve. Valve operators of this type are available for a wide variety of valve sizes and working pressure ranges. Some more details of diploma in petroleum engineering are as under.

In addition to the hydroelectric-type operators, any of the fluid-controlled operators mentioned can be made combination-type operators. By the addition of electric solenoid valves in the fluid-control lines, an electric  signal can be used to control the release of fluid energy  to the valve operator. Combination-type operators of this kind are commonly called “electro pneumatic operators. ”

In electrical control systems, the valve switch may be a mercury switch, a micro switch, or a position  sensing switch. In pneumatic control systems, the  “valve switch” is a three-way pilot valve. The switches may be adjusted to open or close a circuit as the valve opens and closes. Another common use of valve switches is to indicate remotely the operational position (open, closed, etc.) of automatic control valves on wellheads, well manifolds, metering-tank inlets and outlets. In these general applications, valve switches normally will be referred to as “limit switches.” When interlocked with an automatic control system, valve switches perform the very important function of preventing subsequent steps in an automatic operation from proceeding unless certain valves are in the proper position. Other type devices can be used to sense “control” valve positions at intermediate points (or continuously) between the open and closed positions. TSK Training for Skills and Knowledge is the best institute in Rawalpindi Islamabad for Pakistani Students who wants to join diploma in petroleum technology.