BY FUNCTION
Regulating & Throttling Valves
What the valve is asked to do in the line — isolation, non-return, regulation, protection or diversion.
Choosing Regulating & Throttling Valves
Regulating duty means operating at intermediate positions to alter flow. A handwheel is not evidence that a valve tolerates sustained throttling. Select a passage and trim appropriate to the pressure drop, required adjustment and fluid, then decide whether manual or automatic operation is needed.
What to include in the RFQ
- Give the adjustable flow range and corresponding differential pressures.
- Request capacity versus position and the minimum useful adjustment range.
- Identify erosion, noise, cavitation and shut-off requirements separately.
Selection scenario
For a manually adjusted bypass, compare the useful control range with the expected operating points. If the process needs closed-loop adjustment, include the actuator and feedback requirements.
Common selection mismatch
An isolation valve partially closed during commissioning is not automatically a suitable long-term regulating solution.