The RD13 Riser (with NPT connectors) is constructed from Listed CPVC products suitable for fire sprinkler services subject to the limitations and installation requirements of Flameguard CPVC pipe and Spears CPVC fittings. The RD13 Riser incorporates a connection for a VSR-SG flow switch, gauge, and drain/test valve. The connection for the VSR-SG flow switch is capped with a union connection to facilitate the installation and removal of the switch in confined spaces at a later date.