SELECTION CRITERIA
Motor Operated Control Valves (MOVs) are widely used in process industries such as oil and gas, petrochemical, and power plants. These valves use an electric actuator to control the valve position when pneumatic air supply is not available. Proper datasheet preparation is essential to ensure correct valve sizing, material selection, and reliable operation.
Inputs Required for Motor Operated Valve Datasheet Preparation
P&ID (Piping and Instrumentation Diagram)
The P&ID is the primary document used for preparing the valve datasheet. From the P&ID, the following information can be obtained:
- Valve tag number
- Line size
- Line number
- Line specification
- Fail action
- Control philosophy
- Valve location in the process
This information forms the base for selecting the appropriate valve and actuator configuration.
P&ID Legend
The P&ID legend provides details about the symbols and accessories used in the diagram.
From the legend, we can identify:
- Required valve accessories
- Control signals
- Actuator type
- Position indication and control methods
This helps ensure that the selected valve configuration matches the project control philosophy.
piping material specification
The Piping Material Specification is an important reference for selecting the correct valve materials.
Using the PMS, we can determine:
- Valve body material
- Bonnet material
- Trim material
- Packing material
- Gasket material
The selected valve materials must always be compatible with the piping specification to maintain system integrity and safety.
Valve Sizing Calculation
The valve sizing calculation is usually provided by the process engineering team. This document includes the process conditions required for valve selection.
Typical data available in valve sizing calculations include:
- Flow rate (minimum, normal, and maximum)
- Inlet pressure
- Outlet pressure
- Differential pressure
- Fluid type
- Temperature
- Density and viscosity
- Required Cv value
Before finalizing the datasheet, the instrumentation engineer should verify the process data by cross-checking with:
- Heat and Material Balance
- Line List
- Process datasheets
This verification ensures the accuracy and reliability of the valve selection.
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