New York Codes, Rules and Regulations › Title 12 - DEPARTMENT OF LABOR › Chapter I - Industrial Board Of Appeals › Subchapter A - The Industrial Code › Part 14 - Construction, Installation, Inspection And Maintenance Of High Pressure Boilers; Construction Of Unfired Pressure Vessels › Subpart 14-9 - Power Boilers: New Installations › Safety Valves and Safety Relief Valves › Section 14-9.6 - Setting of safety valves and safety relief valves

Current through Register Vol. 46, No. 28, July 10, 2024
(a) One or more safety valves or safety
						relief valves on the boiler proper shall be set at or below the maximum
						allowable working pressure. If additional valves are used the highest pressure
						setting shall not exceed the maximum allowable working pressure by more than
						three percent. The complete range of pressure settings of all the saturated
						steam safety valves on a boiler shall not exceed 10 percent of the highest
						pressure to which any valve is set. Pressure setting of safety relief valves on
						high-temperature water boilers may exceed this 10 percent range.
(b) When two or more boilers which are
						allowed different pressures are connected to a common steam main, all safety
						valves shall be set at a pressure not exceeding the lowest pressure allowed.
Exception:When two or more boilers which are allowed
						  different pressures, are connected to a common steam main, and all safety
						  valves are not set at a pressure not exceeding the lowest pressure allowed, the
						  boiler or boilers allowed the lower pressure shall each be protected by a
						  safety valve or valves placed on the connecting pipe to the steam main; the
						  area or combined area of the safety valve or valves placed on the connecting
						  pipe to the steam main shall not be less than the area of the connecting pipe,
						  except when the steam main is smaller than the connecting pipe, when the area
						  or combined area of safety valve or valves placed in the connecting pipe shall
						  not be less than the area of the steam main. Each safety valve placed on the
						  connecting pipe shall be set at a pressure not exceeding the pressure allowed
						  on the boiler it protects.
Exception:When two or more boilers are allowed to
						  operate at different steam pressures and are connected to a common steam main
						  and their respective safety valves are not set to blow off at the lowest
						  pressure allowed, the headers or outlets from the lower pressure boilers shall
						  be equipped with safety valves, the aggregate capacity of which shall be
						  sufficient to pass the total amount of steam that can be generated in the
						  higher pressure boilers.
Exception:When one or more boilers are used for reserve
						  purposes only and such boilers are not operated in common with the other
						  boilers, nonreturn valves of an approved type may be used in lieu of required
						  safety valves. The nonreturn valves shall be located as close as practicable to
						  the boiler with ample drain between valves.
(c) Where no mechanical feed is attached to a
						boiler, the safety valve shall be set at a pressure of six percent or more
						under the pressure of the main source of supply feeding the boiler. A return
						trap shall not be considered as a mechanical feeding device.