Scubapro Mk16/Mk17 OLD & NEW/Mk18 & TUSA R400 First Stage Tool

The Scubapro Mk 16/Mk17/Mk 18 & TUSA R400 First Stage Tool is designed to assist the technician in several assembly and disassembly operations. These functions are: • Removal and installation of the HP seat. • Removal and installation of the balancing chamber. • Installation of the balanced chamber washer and o’ring. Removing the seat: The stepped end of the tool is inserted into the first stage body so that the intermediate ledge on the tool shaft blocks the hole in the center of the HP seat. A rubber tipped blow gun is positioned on the opposite side of the first stage body, so that the tip is sealed against the center air flow port. While holding the tool in place against the seat, tap the blow gun trigger gently. The seat can be completely removed with a small o’ring pick. Installing the HP seat : The HP seat assembly can be easily installed in the first stage body by placing the seat assembly onto the small end of the shaft and pushing it fully into the internal ledge in the first stage body. Removing/Installing the balancing chamber: One end of the brass tool body has been machined to index with the recessed balanced chamber flats. The balanced chamber can be easily removed and installed with this tool feature. The balanced chamber utilizes standard right hand threads. Installing the balancing chamber washer and o’ring: The recommended method for reassembling the Mark 16 pressure control components is to insert the small washer and o’ring into the balanced chamber. This is done using the small ledge on the tool shaft. The poppet assembly (poppet, poppet guide, spring, and washer) is inserted into the first stage and centered before the balanced chamber, washer, and o’ring are threaded into place. Installing the larger washer with the poppet assembly helps to insure that the poppet stem will be accurately guided into the balancing chamber and through the o’ring and smaller washer.