Techrite Controls Australia...
The B57 regulator is ideally suited for use where inches of water column
or pounds delivery pressure are desired for uses including utility
services, small boilers, and other similar applications. The B57 is
ideal for situations where rapid response is required, such as on/off
loads, and can be utilized to avoid shock problems. In situations where
complete 360 degree rotation of the diaphragm case is desired, the B57
can accommodate any position needed.