225 ILCS 705/15.08

When a compressed air tube fails to discharge, the air line leading to the tube shall be disconnected at the blow-down valve and the tube shall be dragged by means of the air line to a safe place. The tube shall be marketed with warning signs and repair work shall not be done on a tube or shell until the pressure is reduced to zero. Except, however, this provision shall not apply to shells or tubes charged from a shooting valve that can be reversed and the air let out to reduce the pressure in the shell or tube to zero.