In Sporlan's color-coding system

this TXV features a medium temperature charge

This is a fixed-setting mechanical switch calibrated at the factory to 60/35 PSI to ensure consistent safety limits without the risk of field tampering

ensuring stable performance across varying environmental conditions

This is an industry-standard 48-frame motor

McDonnell & Miller 51-S-HD Water Feeder 30067439-890 In Sporlan's color-coding systemThe McDonnell & Miller 51 S HD (Part Number 135800) is a heavy duty head mechanism only replacement designed specifically for Series 51 S mechanical water feeders. Engineered for high capacity systems up to 35,000 sq. ft., this unit is critical for maintaining precise water levels in low pressure steam and hot water boilers. Proportional feed action ensures a steady response to boiler demand, preventing the rapid cycling that stresses high volume