CWQAP - PCST (1) Valve Actuator Questions PDF

Questions 1.Name the parts 5,6,7 and 8 shown in the fig. below. 2. Solenoid converted electrical energy into what type of energy? Objective 4.4 Identify Actuator and Positioner Components A valve actuator is a device that provide force to open, close ,or adjust a valve, In Saudi Aramco, the fou...

Questions 1.Name the parts 5,6,7 and 8 shown in the fig. below. 2. Solenoid converted electrical energy into what type of energy? Objective 4.4 Identify Actuator and Positioner Components A valve actuator is a device that provide force to open, close ,or adjust a valve, In Saudi Aramco, the four most common types of valve actuator are :- 1- Electrical Motor Actuator 2- Pneumatic Actuator 3- Hydraulic actuator 4- Solenoid / Magnetic Actuator 46 Some valves use an electric motor as an actuator. These valves are called motor-operated valve, or MOVs. The motor operated valve has two main parts, the valve itself and a motor –driven screw stem. The motor uses two behaved gears to move the stem up and down. Pneumatic Actuator Electrical Motor Actuator Actuators convert pneumatic pressure into mechanical force that is used to move the control valve to the desired position. Diaphragm-type actuators use air pressure to overcome friction and process pressure to open and close a valve. These actuators normally operate with a positioner. In the positioner, the beam, bellows, and cam work together to position the flapper over the nozzle. The relay uses the back pressure created by the flapper and nozzle to send the right amount of air pressure to the actuator. And the actuator moves the valve stem to open and close the valve. 47 48 49 Questions Refer to the figure below for the following questions: 1. What is the name of the instrument shown below? 2.Name the parts labelled 1 to 7 1:________________ 2:________________ 3:________________ 4:________________ 5:________________ 6:________________ 7:________________ 50 3. What psi do you require to set the actuator to midpoint? ____________ 4. In _____________________________ actuator air pressure forces the diaphragm down which compresses the spring and push the stem down to close the valve. 5. What component tells the actuator to open or close or throttle the valve? ____________________________ 6. Identify the following items: Item 1 Item 2 Item 3 7. What range of signals will a pneumatic-instruments uses to transmit or receive a signal? 8. Which of the followings is a final control element? Control valve Pitch control unit (fin-fan) Louvers (cooling tower) All of the above 51