Using Valve Automation and Control
Valve Automation And Control provides actuators and related parts to be used in all types of applications with specific local conditions. Safety is a primary function, and the demand for reliability in actuators is high, since failure of an actuator may cause toxic leaks in a particular plant. Process-controlled plants have a decades-long operating life, and require that actuators be high quality and designed with corrosion protection. Since a particular valve may be a long distance from the operator, a valve actuator allows the possibility for remote control activation or, alternately, an automatic functionality.
Valve Automation And Control actuators move the valve to open or close utilizing an automatic switch-off procedure when the set tripping point is achieved, in the case of limit seating. In torque seating, the controls are programmed to switch off at the point of exceeding a set torque limit. This serves as protection against excessive torquing; for instance, in the case of a trapped object the controls can discern abnormal twist and switch off from an intermediate position.
Temperature sensors in Valve Automation And Control actuators prevent overheating and protect the motor. In some cases the material can be sticky or abrasive, causing valves to lose functionality. In these cases a valve actuator with additional torque is requested by the designer so the problem can be avoided. Occasionally a manual control feature is added to an electric valve actuator providing extra torque if necessary. In some cases motor current is monitored and will trip the control switch when the limit is reached to prevent burnout during an attempt to move a stuck valve. Actuators with overload protection are available for these applications.
Valve Automation And Control actuators can also be a simple on-off device to turn a valve completely open (on) or closed (off) when signaled. These typically turn off the actuator motor when not in use and do not provide flow control. Proportional control can be achieved by wiring an actuator to open and close gradually in response to the controller, varying flow to reactors, monitoring filling rates, or controlling temperature with heating or cooling liquid flow.
Heating and cooling equipment can utilize Valve Automation And Control actuators for dampers, flue vents, and inlets. Heat pumps, gas and oil furnaces, and boilers all benefit from electric valve actuators of various appropriate types.
Valve Automation And Control actuators are an essential part of the automating process control in a variety of industries and can be found in a spectrum of design and dimension suitable to the specific application required. They can be classified according to their movement, the distance the closing element must cover to completely open or close the valve. Typically, butterfly valve discs swivel on an axis to open or close the passage, globe valve discs move in a short linear stroke, and the gate valve disc moves to cover the entire opening of the valve. Each movement requires a particular type of actuator in order to function correctly, some by multiple complete turns and some by partial turns. The amount of torque and thrust resistance vary considerably and the choice of valve actuator must be carefully considered for optimal performance.