New York Codes, Rules and Regulations › Title 12 - DEPARTMENT OF LABOR › Chapter I - Industrial Board Of Appeals › Subchapter A - The Industrial Code › Part 4 - Low Pressure Boilers › Subpart 4-5 - Specific Requirements For Low Pressure Heating System Boilers › Section 4-5.2 - Safety valves for low pressure steam boilers

Current through Register Vol. 46, No. 28, July 10, 2024
(a) Capacity. A low pressure steam boiler
					 shall include a safety valve or valves of a capacity such that with the heat
					 generating equipment operating at maximum, the steam pressure shall not rise
					 more than five psi gage above the maximum allowable working pressure with all
					 valves open. If the minimum valve capacity in pounds per hour is calculated it
					 shall be determined by dividing by 1,000 the maximum Btu output at the boiler
					 nozzle obtainable from the heat generating equipment, or by multiplying the
					 square feet of heating surface by the values given in the following table:
Minimum pounds of steam per hour per square foot of
						surface
[Note: The following TABLE/FORM is too wide to be
						displayed on one screen. You must print it for a meaningful review of its
						contents. The table has been divided into multiple pieces with each piece
						containing information to help you assemble a printout of the table. The
						information for each piece includes: (1) a three line message preceding the
						tabular data showing by line # and character # the position of the upper
						left-hand corner of the piece and the position of the piece within the entire
						table; and (2) a numeric scale following the tabular data displaying the
						character positions.]
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						******** This is piece 1. -- It begins at character 1 of table line 1. ********
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						Boiled heating surface Hand-fired Stoker-fired Oil, gas, or Hand-fired
						pulverized-fuel-fired Fire-tube 5 7 8 8 boilers Water-tube 6 8 10 8 boilers
						1...+...10....+...20....+...30....+...40....+...50....+...60....+...70....+.
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						******* This is piece 2. -- It begins at character 77 of table line 1. ********
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						Waterwall surface Stoker-fired Oil, gas, or pulverized-fuel-fired 10 14 12 16
						77......+...90....+....0....+...10....
Note: When a boiler is fired only by a gas having a heat
						value not in excess of 200 Btu per cubic foot, the minimum safety valve
						relieving capacity may be based on the values given for hand-fired boilers
						above.
The minimum capacity of the valve or valves shall be
						governed by the capacity marking on the boiler.
(b) Increased capacity. When operating
					 conditions are changed or additional boiler heating surfaces installed, the
					 valve capacity shall be checked and increased if necessary to meet the new
					 conditions. Necessary additional valves may be installed on the outlet piping,
					 providing there is no intervening valve nor any other branching pipes between
					 the additional valves and the boiler.
(c) Accumulation test. If the total capacity
					 of safety valves is not otherwise ascertained they shall be subjected to an
					 accumulation test.
(d) Type.
					 Required safety valves shall be of the spring-pop type, adjusted and sealed to
					 discharge at a pressure not to exceed 15 psi gage. The seats and disks shall be
					 of suitable material to resist corrosion.
(e) Size. No safety valve for a low pressure
					 steam heating boiler shall be smaller than 3/4 inch except in case the boiler
					 and radiating surfaces are a self-contained unit. No safety valve shall be
					 larger than 41/2inches. The inlet opening shall have an inside diameter equal
					 to or greater than the seat diameter.
(f) Lifting device. Each safety valve for a
					 low pressure steam heating boiler shall have a substantial device which will
					 positively lift the disk from its seat at least 1/16 inch when there is no
					 pressure on the boiler.