Knox Box Standpipe Lock 2 1/2" Female NH/NST Locking Cap Model:4023 (6.0 TPI x 3.187 OD) It is a finer thread
Baker’s notes & crumb story
Description
Knox Box Standpipe Lock 2 1 2" Female NH NST Locking Cap Model:4023 (6.0 TPI x 3.187 OD) It is a finer thread It is a finer thread than National Pipe Thread (NPT) keeping pipes clean of debris to ensure the delivery of high pressure water flow to fire sprinkler systems