When performing a head mechanism replacement or annual inspection

opening the 1/8" orifice to discharge gas before automatically resealing when the liquid returns

allowing the system to resume normal operation safely after cooling

If the ceramic insulator is cracked or the boiler is frequently locking out on "No Flame

For technicians managing hydronic heating systems

Liebert B-005AS Sheave 30067439-890 When performing a head mechanismThe Liebert B 005AS Sheave is a high precision, single groove cast iron sheave engineered for critical environment HVACR systems. Built with a 7 8" finished bore and a 4. 75" outside diameter, this component is designed to maintain exact blower speeds in Liebert precision cooling units. As an OEM replacement part, it ensures proper belt alignment and consistent torque transmission, which are vital for preventing premature bearing failure and