If a control valve is no longer manufactured or available, what two characteristics must be known to select an equivalent replacement?

If a control valve is no longer manufactured or available, what two characteristics must be known to select an equivalent replacement?

• A. Size and material
• B. Brand and model
• C. Size and type
• D. Operating temperature and pressure

Answer: (C)

When replacing a control valve that's no longer available, you need to match how it fits in the system and how it behaves. The two essential characteristics are size and type. Size ensures the valve will physically connect to the piping and deliver the appropriate flow capacity (Cv) to meet process requirements. Type describes the valve design and how it modulates flow, which determines the control characteristics you’ll reproduce (for example, a globe-style throttling valve versus another design with a different flow response). Together, size and type ensure the replacement both fits the system and provides a similar control behavior. Other factors like brand, specific materials, or exact operating conditions can be checked afterward for compatibility, but they don’t guarantee a proper functional match on their own.

When replacing a control valve that's no longer available, you need to match how it fits in the system and how it behaves. The two essential characteristics are size and type. Size ensures the valve will physically connect to the piping and deliver the appropriate flow capacity (Cv) to meet process requirements. Type describes the valve design and how it modulates flow, which determines the control characteristics you’ll reproduce (for example, a globe-style throttling valve versus another design with a different flow response). Together, size and type ensure the replacement both fits the system and provides a similar control behavior. Other factors like brand, specific materials, or exact operating conditions can be checked afterward for compatibility, but they don’t guarantee a proper functional match on their own.