Each steam-discharge outlet, except safety valve, reheater inlet and outlet, or superheater inlet connections, must be fitted with a stop valve located at an accessible point in the steam-delivery line and as near to the boiler nozzle as convenient and practicable. When the outlets are over two inches pipe size, the valve or valves used on the connection must be the outside-screw-and-yoke rising-spindle type to indicate at a distance by the position of its spindle whether it is closed or open. A plug-cock-type valve may be used provided the plug is held in place by a guard or gland, and it is equipped to indicate at a distance whether it is closed or open and it is equipped with a slow-opening mechanism.
Minn. R. agency 151, ch. 5225, BOILER SAFETY, pt. 5225.4600
Statutory Authority: MS s 183.44; 183.465; 183.466; 326B.964; 326B.966