Emergency Shut-off - PHMSA Letter Request

During an inspection a truck was found with a unique emergency shutoff. The trailer was found to have 3 glad hand air hookups, the service and emergency glad hands were as normal, however the 3rd glad hand connection functioned as the trailers emergency shutoff. From the explanation the driver gave when he stops to make a drop off he must disconnect the emergency side glad hand and connect it to the 3rd glad hand connection, this connection airs up the system to open the internal valve. If an emergency occurs a person would need to disconnect the glad hand to stop airing the system and close the internal valve.

There are 2 reasons this would need to be addressed. 1st this is a unique shutoff system that inspectors would have little to no knowledge of and could incorrectly list this as a violation. 2nd due to this systems method of operation inspectors and emergency responders would have a difficult time understanding how to activate the shutoff.

CVSA should request a letter of interpretation from PHMSA on this item to clarify if this meets the requirements for emergency shutoff's of cargo tanks under 49 CFR 178.345-11(b)(1)(i). Additionally or alternatively an inspection should be created to ensure that violations are not incorrectly noted on inspections.