Motor Operated Valve (MOV) is one of the most important items in process and piping system. These valves are generally of large size and are used in different conditions. Motor operated valves can be of various types e.g. Gate/ Ball/ Butterfly etc. with electric motor operated actuator for control. Make of motors and valves are different.
Motor operated valves are often called as On-Off valves also as they serve the purpose of full open or full close services in pipelines. For example cooling water lines, process pipelines where controlling of fluid is not required can use motor operated valves for turning flow on or off. These valves are not used for throttling purpose.
There is an interface/co-ordination requirement amongst piping-electrical-instrumentation-process engineers designing a process plant along with the vendor co-ordination for procurement of motor operated valves.
Use of MOV's is specified in following conditions
- Whenever frequent operation is required.
- Valves located in remote, inaccessible or hazardous places.
In order to procure the best MOV suited for the application, the user has to provide the valve manufacturer with all the necessary information to select and design a suitable MOV.
- Process conditions of the fluid flowing through the valve. (i.e fluid flowrate, inlet pressure to the valve, design pressure of the line etc). Pump shut-off pressure is also required.
- Pipe size and pipe class also need to be mentioned.
- Valve body type (ball, gate, butterfly etc), end connection & rating and seat tightness is also required (Class IV, V etc.) by piping.
- Motor voltage to be provided by electrical along with motor insulation class.
- Information about explosion class and explosion protection.
- Opening and closing time required for MOV.
- Instrumentation to provide information like Form rating, position indicator, motor starter, selector switch for remote/local operation and open-close terminal blocks for remote indication.
This datasheet along with Requisition form is then sent to suppliers/vendors who later on submit technical bids for respective MOV’s / valves.
Typical datasheet for the MOV is shown below: