31. Pressure installations must be approved by the Board before they are put into service, except in the following cases:(1) installation of a mobile boiler or pressure vessel at the same location for a period of 3 weeks or less;
(2) the work pertains solely to accessories or piping and is performed by an installer holding a permit;
(3) installations addressed in the quality control program, approved by the Board, which are allowed to be carried on without approval.