Amerex Trip Assembly Gas Wet 12740 - OEM

The Amerex 12740 is the gas trip assembly for mechanical gas shutoff valves in Amerex KP restaurant fire suppression systems. In plain terms: this is the mechanism that physically closes the gas valve when the suppression system fires. When the KP system activates, the piston-style trip unit pulls a cable that unlatches the gas valve, allowing its internal spring to close the valve and safely shut off gas flow to the protected cooking equipment. The 12740 is the link between the suppression system actuation and the gas shutoff that fire code requires.

NFPA 96 requires that gas cooking equipment be automatically shut off when a kitchen fire suppression system activates. The Amerex 12740 trip assembly is how the Amerex KP system accomplishes this mechanical gas shutoff. Without a functioning trip assembly, the gas valve won't close when the system fires — meaning gas continues to feed a potential reignition of the grease fire even after the wet chemical agent has been discharged. One important installation detail: the 12740 includes a red vinyl cap that must be correctly installed. Improper cap installation may prevent the valve from closing properly — follow the Amerex installation documentation precisely for this component.

The 12740 is designed for use with Amerex KP mechanical gas shutoff valves (12790, 12791, 12792) and is also compatible with ASCO and Ansul pull-to-close gas valves per Amerex documentation. Available through authorized Amerex distributors. Test the trip assembly function at every semi-annual NFPA 17A and NFPA 96 inspection, and replace if the mechanism shows any binding, corrosion, or mechanical damage.

Semi-Annual Inspection Test

At every semi-annual NFPA 17A and NFPA 96 inspection, the technician will trigger a simulated system discharge and verify the 12740 trip assembly pulls the gas valve cable fully and the gas valve closes completely. The gas valve must close within the time frame specified in the Amerex KP system documentation. A trip assembly that binds, fails to pull, or doesn't fully close the gas valve is an immediate NFPA 96 deficiency. The system must be repaired before it can be returned to service. After a successful test, the gas valve must be manually reset and the system re-armed before leaving the site.

Post-Discharge Service

After any KP system discharge, inspect the 12740 trip assembly for damage from the actuation event. Check the piston mechanism for deformation and the cable attachment point for any damage. Replace if any mechanical damage is found. Reset the gas valve manually before re-arming the system. The gas valve does not reset automatically and gas will not flow to cooking equipment until it is manually reset by a trained technician.

My gas didn't shut off when the system fired. Is the 12740 the problem?

A gas valve that doesn't close when the system activates could be caused by a failed or binding 12740 trip assembly, a broken or disconnected cable between the trip assembly and the gas valve, or a mechanical problem in the gas valve itself (12790, 12791, or 12792). Your fire suppression service technician will inspect the complete gas shutoff chain trip assembly, cable, and valve to identify the failure point. This should also have been caught at the most recent semi-annual inspection if the trip test was properly conducted.

Does the 12740 work with both natural gas and LP gas valves?

The 12740 trip assembly is a mechanical cable-pull device — it works the same way regardless of whether the gas valve it's connected to is plumbed for natural gas or LP gas. The valve itself (12790, 12791, or 12792) is UL listed for both gas types. The 12740 simply pulls the cable that releases the valve's spring-loaded closure mechanism, independent of the gas type flowing through the valve.