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Virginia Administrative Code (Last Updated: January 10, 2017) |
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Title 16. Labor and Employment |
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Agency 25. Safety and Health Codes Board |
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Chapter 50. Boiler and Pressure Vessel Regulations |
Section 530. Air and ventilation requirements
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A permanent source of outside air shall be provided for each boiler room to permit satisfactory combustion of the fuel as well as proper ventilation of the boiler room under normal operating conditions.
A. The total requirements of the burners for all fired pressure vessels in the boiler room must be used to determine the louver sizes whether fired by coal, oil or gas; however, the minimum net free louvered area must not be less than one square foot. The following table or formula shall be used to determine the net louvered area in square feet:
Input BTU Per Hour
Required Air
Cu. Ft./Min.Min. Net Louvered Area
Sq. Ft.500,000
125
1.0
1,000,000
250
1.0
2,000,000
500
1.6
3,000,000
750
2.5
4,000,000
1,000
3.3
5,000,000
1,250
4.1
6,000,000
1,500
5.0
7,000,000
1,750
5.8
8,000,000
2,000
6.6
9,000,000
2,250
7.5
10,000,000
2,500
8.3
(BTU per hour - 100) x 1.5
÷
300
=
Min Net Area Req. Sq. Ft.
60
B. When mechanical ventilation is used instead of subsection A of this section, the supply of combustion and ventilation air to the boiler room and the firing device shall be interlocked with the fan so the firing device will not operate with the fan off. The velocity of the air through the ventilating fan shall not exceed 500 feet per minute and the total air delivered shall be equal to or greater than shown in this section.
Historical Notes
Derived from VR425-01-75 § 4.15, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.