MECH™ Grooved Normally Closed Butterfly Valve with Tamper Switch
The MECH™ Butterfly Valve is a grooved, normally closed butterfly valve with tamper switch intended for fire sprinkler system service where sectional control and valve supervision are required. In fire protection piping, control valves are used to isolate portions of a system for maintenance, inspection, or testing, and supervisory monitoring helps reduce the risk of a valve being left in the wrong position. The “normally closed” configuration is commonly specified where the valve’s default state is intended to remain closed until opened for a planned function, supporting system arrangements that rely on controlled activation or dedicated sectional isolation. This model includes a tamper (supervisory) switch intended to connect to a fire alarm supervisory circuit, providing valve-position monitoring so that off-normal conditions can be signaled if the valve is not in its expected operating position. The valve body is manufactured from ASTM A536, 65-45-12 Ductile Iron to provide strength and durability for demanding water service, and it is supplied with a high-visibility Red finish to support identification in risers, valve stations, and mechanical room installations.
This valve uses a Grooved connection type, supporting common grooved-coupling piping layouts used throughout fire sprinkler installations. It is rated for a maximum working water pressure of 300 PSI and is intended to operate within a rated working temperature range of 32F to 176F (0C to 80C), aligning with typical above-freezing fire protection water supply conditions. Butterfly valves are frequently selected for fire protection service because they provide effective shutoff in a compact valve envelope and can be operated quickly when isolation is required. As noted in manufacturer guidance for grooved butterfly valves, correct handling and installation practices are important, including disc position awareness during assembly so the disc does not interfere with adjacent piping or couplings during installation.
The valve family maintains consistent, specification-friendly attributes across available configurations—ductile iron construction, grooved ends, a Red exterior finish, supervisory monitoring via tamper switch, and a 300 PSI working-pressure rating with the listed temperature range—supporting consistent design documentation across a range of system layouts. This valve is UL Listed and FM Approved.
This valve is also available in the following sizes: 4 in. NPT Valve; 6 in. NPT Valve; 8 in. NPT Valve; 10 in. NPT Valve.

