while the swing-out center section allows for easy seat and seal maintenance without fully removing the valve from the line

and lighting circuits without the complexity of electronic controls

The activated carbon air filter construction ensures maximum surface area for gas-phase adsorption

This ensures linear heat output for heating and cooling coils

which is not standard on basic 40VA models

Siemens Building Technology S55180-A158 Actuator 322838-752 while the swing-out center sectionThe Siemens Building Technology S55180 A158 (Model SSF161. 05U) is a high precision proportional electronic actuator designed for seamless integration with 599 Series zone valves. Engineered for performance in VAV systems, fan coil units, and chilled ceiling applications, this 24Vac dc actuator utilizes a 0 10 Vdc positioning signal to provide linear control with a 1 10 inch (2. 5 mm) stroke. As a non spring return (NSR), fail in place unit, it