NRv2® LoFlo Backflow Prevention Check Valve - Fluid category 2. Technical Specifications WRAS certified as being compliant with all water industry specifications for materials. Pressure tested to 50 Bar Thread: male / female 1.5” BSP thread (standard concentric meter thread) in accordance with Water Industry Standard (WIS 4-37-01) Certified to offer whole site protection to Back Flow Category 2 Installation Guides Simply screw NRv2 ® between the thread of the meter (concentric type) and the thread of the manifold Locate in the Groundbreaker or boundary box as “standard”