whereas the standard 51 is limited to 35 PSI on the water supply side and lower vessel pressures

minimizing pressure drop while maintaining a tight shut-off in critical flow paths

or electric furnaces and 2-wire hydronic systems

making it ideal for noise-sensitive indoor air handling environments

Reliable Flame Sensing: Utilizes remote flame sensing technology via a dedicated sensor lead for more accurate flame detection compared to internal sensing models

Johnson Controls D-3246-2 Damper Actuator 30067439-890 whereas the standard 51 isThe Johnson Controls D 3246 2 is a heavy duty pneumatic damper actuator engineered for precise control of large dampers in commercial HVAC systems. This swivel mounted piston style actuator features a 6 inch stroke and a 23. 4 square inch effective diaphragm area, delivering reliable linear motion within an 8 13 psi spring range. To ensure high accuracy positioning especially in high velocity airflow or high friction applications, this model includes