Featuring a 3/8" SAE flare by 1/4" MPT connection

It maintains the same physical dimensions and hole patterns across compatible 47

If you notice signs of compression set

Built to integrate seamlessly with the Maxitrol RV81

always use a new gasket

McDonnell & Miller 310800 Gasket Featuring a 3/8" SAE flareThe McDonnell & Miller 310800 Gasket is a critical sealing component engineered specifically for the 21 Series and 221 Series float operated water feeders. Also identified by model number 21 12, this 4 hole valve body gasket provides a high integrity seal between the valve assembly housing, the strainer body, and the feeder flange. In steam and hot water boiler applications, maintaining a leak proof connection at the make up water feeder is essential