Schneider Electric (Barber Colman) PNV-251 Diaphragm

The Schneider Electric (Barber Colman) PNV-251 is a high-performance replacement diaphragm specifically engineered for pneumatic actuator maintenance in high-temperature environments. Designed for seamless integration with the MK-46xx series, including MK-4601, MK-4611, and MK-4621 actuators, this component ensures consistent proportional pneumatic control for hot water and chilled water systems. Constructed from beaded molded neoprene, the PNV-251 provides a robust seal and 11 sq. in. of effective area, maintaining system integrity even under peak air pressure ratings up to 30 psig.

When servicing HVAC valves such as the VB-7xxx or discontinued VB-9xxx series, switching to this high temperature diaphragm is necessary for ambient operating conditions reaching up to 220°F. For contractors overseeing building automation systems, utilizing genuine Schneider Electric PNV-251 parts prevents premature fatigue often seen with standard-rated components in extreme thermal cycles. This field-replaceable unit allows for direct installation into the actuator housing using existing mounting hardware, restoring critical damper and valve positioning precision without requiring a full actuator replacement.

• High-Temperature Rating: Specifically formulated to withstand ambient temperatures up to 220°F (104°C), far exceeding standard diaphragm limits.
• Precise Actuation: Maintains an 11 sq. in. effective area for accurate control of MK-46xx series pneumatic actuators.
• OEM Compatibility: Precision-molded beaded neoprene construction ensures an airtight fit with Schneider Electric and Barber Colman valve assemblies.
• Pressure Resilience: Engineered to handle maximum air pressure ratings of 30 psig (207 kPa) for reliable HVAC system performance.

Is the PNV-251 compatible with standard MK-4611 actuators?
Yes, the PNV-251 is the direct high-temperature upgrade for the standard PNV-002 diaphragm typically found in MK-4611 and MK-46xx series actuators.

What material is used for the PNV-251 diaphragm?
It is manufactured from high-grade beaded, molded neoprene, optimized for thermal resistance and repeated cycling in pneumatic applications.

Can I use this diaphragm in any mounting position?
While the diaphragm itself functions in any orientation within the housing, the actuator should generally be mounted in an upright position above the horizontal center line of the valve body for optimal longevity.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.