Watts 0556018 Valve R 22 Service technicians typically specify the Service technicians typically specify the SLG0123 when servicing Trane and American Standard units to maintain factory airflow specifications and mechanical balance Enhanced Durability: Equipped with automatic reset thermal overload protection for safe operation in extreme temperatures Its durable construction includes tamper resistant bonnet screws and a thermo bonded coated thermostat to prevent mineral buildup and maintain long term performance It maintains the same 1 inch sizing and 125 psi pressure setting while upgrading the material to current lead free standards