Masoneilan 3" Model 88U-25125 Diaphragm Control Valve | 1" Body | 150 ANSI | SVI-2 Valve Positioner | Air Filter Regulator

What pressure, flow and temperature is it rated for?

The valve body is rated for 150 ANSI pressure. Flow capacity and temperature range are not specified in the listing—ask the seller for the Cv value and temperature limits for the specific trim configuration. Diaphragm control valves in this class typically handle temperatures up to 200-250°F depending on diaphragm material, with Cv ranging from approximately 1 to 12 for a 1" body.

What materials are the wetted parts?

The valve body is 316 stainless steel. The listing does not specify trim material, seat material, or diaphragm compound—ask the seller for complete materials of construction including the plug, seat ring, stem, and diaphragm. On Masoneilan 88U series valves, trim is typically 316 stainless or hardened stainless depending on the service, with diaphragms available in various elastomers and PTFE-lined configurations.

What should I inspect before putting it into service?

The listing states this valve must be re-serviced before use for proper calibration and reliability. At minimum, inspect the diaphragm for cracks or stiffness, verify seat tightness and trim condition, check the SVI-2 positioner for calibration and response, and confirm the 78-40 filter regulator output pressure and filter element condition. Stroke the valve through its full range while monitoring positioner feedback to identify any binding, hysteresis, or dead band issues that would require actuator rebuild or trim replacement.