It is installed in the vapor adaptor valve tointerlock among the pneumatic control.Two-ways-I-structure with automaticback when the air pressure is present, itgoes back to the original position after release.
It is a part of the pneumatic control system.It is connected with the pneumatic controlblock's outlet hole. The tanker doing theloading job, when an emergencyhappened, push this button, the pneumaticcontrol block will stop working. As usual, itwill be installed at the end of the tanker orfar from the loading position for easyoperation
