NDAC 33.1-14-09-20
Bottom blowoff and drain valves
Cite as N.D. Admin. Code § 33.1-14-09-20
1.
Each steam boiler having a capacity over twenty-five gallons [94.6 liters] must have a bottom
blowoff connection fitted with a valve or cock connected to the lowest water space practicable
with a minimum size as shown below:
Minimum Required Safety Valve Capacity in
Pounds of Steam/Hour
Steam Boiler Blowoff Piping Valve Size,
Inches (Min.)
Up
to
500
3/4
501
to
1,250
1
1,251
to
2,500
1 1/4
2,501
to
6,000
1 1/2
6,001
and
larger
2
2.
Each hot water boiler and each steam boiler having a capacity not exceeding twenty-five
gallons [94.6 liters] must have a drain valve connected to the lowest water space practicable.
The minimum size of this drain valve is three-quarter inch [1.9 centimeters].