A valve assembly including a base portion and a cap portion attached to the base portion. The valve assembly also includes a biasing member disposed between the base portion and the cap portion. The biasing member is adjacent a perforation formed in the cap portion. A shuttle assembly is in contact with the biasing member. The shuttle assembly includes a shuttle and a plug member. The plug member is attached to the shuttle.

A valve assembly, includes a valve body having an inlet portion, an outlet portion, and a constriction portion; a shaft positioned within the valve body and extending along a longitudinal axis of the valve body; a cone provided within the inlet portion and configured to move along the shaft; a spring configured to bias the cone away from the constriction and positioned between a first piston fixed to the cone and a second piston fixed to the shaft; and an adjustable spacer positioned between a fixed position on the shaft and the second piston. The adjustable spacer is adjustable in length to change an effective length of the adjustable spacer and change a position of the second piston on the shaft.

A system and method for maintaining the integrity of a dry pipe sprinkler system. The system includes an auxiliary drain including a main collection pipe, a heater having a bracket configured to attach the heater to the main collection pipe of the auxiliary drain, the bracket including a deflector configured to direct heat from the heater onto the main collection pipe, and a self-draining apparatus configured to receive excess water from the auxiliary drain.

A relief valve for a backflow preventer includes a plunger, a lock nut, and a seal. The plunger has a female fastening section and a first seal engagement surface. The lock nut has a male fastening section and a second seal engagement surface. The male fastening section is received by the female fastening section to bring the first seal engagement surface toward the second seal engagement surface. The seal is positioned between the first seal engagement surface and the second seal engagement surface.