Brass bodied WRAS approved (certificate N. 2007001) pilot operated diaphragm valve for use with TraceTek and AquiTron leak detection systems. Normally Closed (fail safe), with manual release override. Suitable to shut off water (verify suitability of fluid with materials in contact). 230VAC 100% duty cycle solenoid coil. Option to mount in any position apart from coil facing down (coil facing up is recommended). The AT-V-NC solenoid valve is a fail-safe normally closed valve. Meaning it is closed in an unpowered state. In an emergency situation it is possible to manually override this and open the valve without power. A small flat bladed screwdriver is required. This is inserted as shown in Figure 1 and the screw head rotated quarter of a turn in a clockwise direction. Important: For normal operation the grub screw head must be returned to its original position.