Conn. Agencies Regs. § 29-232-94
The minimum size of ferrous or nonferrous pipes connecting a water column to a steam boiler shall be one inch. No outlet connections, except for damper regulator, feedwater regulator, steam gages, or apparatus which does not permit the escape of any steam or water except for manually operated blowdowns, shall be attached to a water column or the piping connecting a water column to a boiler. If the water column, gage glass, low-water fuel cutoff, or other water level control device is connected to the boiler by pipe and fitting, no shut off valves of any type shall be placed in such pipe, and a cross or equivalent fitting to which a drain valve and piping may be attached shall be placed in the water piping connection at every right angle turn to facilitate cleaning.
The water column drain pipe and valve shall be not less than 3/4 in. pipe size.
The steam connections to the water column of a horizontal firetube wrought iron boiler shall be taken from the top of the shell or the upper part of the head, and the water connection shall be taken from a point not above the center line of the shell. For a cast iron boiler, the steam connection to the water column shall be taken from the top of an end section or the top of the steam header, and the water connection shall be made on an end section not less than 6 in. below the bottom connection to the water gage glass.
Conn. Agencies Regs. § 29-232-94