12790 Amerex 3/4 Mechanical Gas Valve - OEM

The Amerex 12790 is a 3/4-inch brass pull-to-close mechanical gas valve designed specifically for Amerex KP kitchen fire suppression systems. Under normal operation, the valve is held open by a latch mechanism. When the system activates, a trip cable from the Amerex MRM or PRM release module pulls the latch, allowing an internal spring to close the valve and shut off the gas supply safely and automatically — preventing fuel from reaching the protected cooking appliances during and after the wet chemical suppression discharge.

The 3/4-inch pipe size of the 12790 is the smallest in the Amerex mechanical gas valve series, making it the correct gas shut off valve for range applications where the gas supply line to a single small cooking appliance — a countertop fryer, small range, or standalone griddle — runs through 3/4-inch pipe. Selecting the correct valve size for the actual pipe size is essential: an undersized valve creates gas flow restriction that affects appliance performance, while an oversized valve may not fully seal under the lower pressure conditions of a small-appliance gas line.

The 12790 is UL listed for both natural gas and LP gas service. It is part of the same Amerex mechanical gas valve family as the 12791 (1-inch) and 12792 (1-1/4-inch), all available through authorized amerex distributors as standard amerex fire suppression system parts. The commercial kitchen gas shut off valve function of the 12790 satisfies the NFPA 96 requirement for automatic gas shutoff in Amerex KP-protected cooking configurations. Test at every semi-annual NFPA 17A and NFPA 96 inspection and document in the fire suppression system inspection record.

Install the 12790 in the 3/4-inch gas supply line upstream of the protected appliance per NFPA 96, the amerex kp system manual, and applicable local gas code. Identify the gas safety shut off valve location with gas shut off signage. Connect the trip cable to the Amerex MRM or PRM module per the amerex kp system manual cable routing specifications — verify the routing distance is within the maximum approved cable length. Test the gas auto shut off valve at every semi-annual NFPA 17A and NFPA 96 inspection. A gas safety valve shut off failure is an immediate red-tag deficiency. Document in the fire suppression system inspection record. The manual reset must be accessible and operable by kitchen personnel after discharge without tools.

Can I use the 12790 on a gas dryer or gas fireplace gas shut off valve application?

The 12790 is specifically listed for use in Amerex KP kitchen fire suppression system installations. While its 3/4-inch gas shut off valve mechanics are similar to gas dryer shut off valve and gas fireplace gas shut off valve applications, its UL listing is specific to kitchen suppression system integration. For non-suppression gas shutoff applications consult the applicable gas code and use a valve listed for that specific application.

Is the 12790 reset automatic after discharge?

No. The 12790 requires manual reset after each activation. After a system discharge, trained personnel must manually reset the pull-to-close latch before gas flow can resume to the protected appliance. This intentional design prevents cooking equipment from being re-energized before the suppression system has been serviced and recharged — an important safety step in the post-discharge kitchen reopening procedure.