66. The holder of a 5th class heating and steam engine certificate or of a Class D or C certificate for refrigerating apparatus, on 1 September 1981, has his certificate exchanged for a 4th class heating and steam engine certificate or for a Class B certificate for refrigerating apparatus, as the case may be; such certificate is valid only for the installation that the stationary engineman was supervising or operating on 1 September 1981 and provided that the capacity of the installation is not modified by the addition of new stationary engines.
R.R.Q., 1981, c. M-6, r. 1, s. 66.