Bulldog Winch Drain Cock 1/4in NPT. The typical procedure for compressing air is to build air pressure in the tank compress this air and then leave it sitting in water or leave the water in the air for longer periods of time. The Compressed Air will accumulate water in the tank that needs to be drained. The Drain Cock provides and quick and convenient way to drain this water from the air tank. Compressed Air will accumulate water in the tank that needs to be drained. The Drain Cock provides and quick and convenient way to drain this water from the air tank. Brass with rubber sealing ring 1/4in NPT threads. Specifications for Bulldog Winch Drain Cock: Manufacturer: Bulldog Winch Fabric/Material: Brass Quantity: 1 Diameter: 1/4 in Features of Bulldog Winch Drain Cock Compressed Air will accumulate water in the tank that needs to be drained The Drain Cock provides and quick and convenient way to drain this water from the air tank Brass with rubber sealing ring 1/4in NPT Threads Package Contents: Bulldog Winch Drain Cock Bulldog Winch 42014: Drain Cock 1/4in NPT