(a)

1. (1) The minimum size of pipes connecting the water column to a boiler shall be one inch (1”).
2. (2) For pressures of four hundred pounds (400 lbs.), or over, lower water column connections to drums shall be provided with shields, sleeves, or other suitable means to reduce the effect of temperature differentials in the shells of heads.
3. (3) Water glass fittings or gauge cocks may be connected directly to the boiler.

(b)

1. (1) The design and materials of a water column shall comply with the requirements of the ASME code.
2. (2) Water columns made of cast iron in accordance with Specification SA-48 may be used for maximum boiler pressures not exceeding two hundred fifty pounds per square inch (250 psi).
3. (3) Water columns made of malleable iron in accordance with Specification SA-47 may be used for maximum boiler pressures not exceeding three hundred fifty pounds per square inch (350 psi).
4. (4) For higher pressures, steel construction shall be used.

(c)

1. (1) The steam and water connections to a water column or a water gauge glass, including all pipes, fittings, valves, and drains, shall comply with requirements of the ASME code, as adopted.
2. (2) These connections shall be such that they are readily accessible for internal inspection and cleaning.
3. (3) Some acceptable methods of meeting this requirement would be by providing a cross or fitting with a back outlet at each right angle turn to permit inspection and cleaning in both directions, or by using pipe bends or fittings of a type which do not leave an internal shoulder or pocket in the pipe connection and with a radius of curvature which will permit the passage of a rotary cleaner.
4. (4) The water column shall be fitted with a drain cock or drain valve with a suitable connection to the ashpit, or other safe point of waste, and if the water connection thereto has a rising bend or pocket which cannot be drained by means of water column drain, an additional drain shall be placed on this connection in order that it may be blown off to clear any sediment from the pipe.
5. (5) The water column blowoff pipe shall be at least three-fourths-inch pipe size.