Designed for use in grid systems or any sprinkler system where pressure relief is required. The adjustable pressure relief valve can be adjusted from 75 to 175 psi. Adjustment to the desired pressure is achieved with the use of an approved fire sprinkler system pressure gauge. The adjustment cap is "diamond" knurled for easy adjustment. The body is cast bronze and marked with directional arrows for proper flow indication. The pressure markings on the adjustment cap are for reference only. Use the system gauge for proper relief setting.