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 14-9.10 - Safety valve connections

Current through Register Vol. 46, No. 28, July 10, 2024
(a) When
						two or more safety valves are used on a boiler, they may be mounted either
						separately or as twin valves made by placing individual valves on Y bases, or
						duplex valves having two valves in the same body casing. Twin valves made by
						placing individual valves on Y bases, or duplex valves having two valves in the
						same body, shall be of approximately equal capacity. When not more than two
						valves of different sizes are mounted singly, the relieving capacity of the
						smaller valve shall be not less than 50 percent of that of the larger valve.
						When a boiler is fitted with two or more safety valves or safety relief valves
						on one connection, this connection to the boiler shall have a cross sectional
						area not less than the combined areas of inlet connections of all the safety
						valves with which it connects and shall also meet the requirements of section
						14-9.10(b)  of this Subpart.
(b) The
						safety valve or safety relief valve or valves shall be connected to the boiler
						independent of any other steam connection, and attached as close as possible to
						the boiler or normal steam flow path, without any unnecessary intervening pipe
						or fitting. Such intervening pipe or fitting shall be not longer than the
						face-to-face dimension of the corresponding tee fitting of the same diameter
						and pressure under the corresponding American National Standard. Every safety
						valve shall be connected so as to stand in an upright position, with spindle
						vertical. On high temperature water boilers of the watertube forced circulation
						type, the valve shall be located at the boiler outlet. Safety valves may be
						attached to drums or headers by welding provided the welding is done in
						accordance with Code requirements. Safety valves may be attached to drums or
						headers provided the welding is done in accordance with the requirements of
						this Part.
(c)
(1) The opening or connection between the
						boiler and the safety valve shall have at least the area of the valve inlet. No
						valve of any description shall be placed between the required safety valve or
						safety relief valve or valves and the boiler, nor on the discharge pipe between
						the safety valve or safety relief valve and the atmosphere. When a discharge
						pipe is used, the cross-sectional area shall be not less than the full area of
						the valve outlet or of the total of the areas of the valve outlets discharging
						thereinto and shall be as short and straight as possible and so arranged as to
						avoid undue stresses on the valve or valves.
(2) All safety valve or safety relief valve
						discharges shall be so located or piped as to be carried clear from running
						boards or platforms. Ample provision for gravity drain shall be made in the
						discharge pipe at or near each safety valve, and where water of condensation
						may collect. Each valve shall have an open gravity drain through the casing
						below the level of the valve seat. For iron and steel-bodied valves exceeding
						21/2inch size the drain hole shall be tapped not less than three-eighths inch
						pipe size.
(3) Discharge piping
						from safety relief valves on high temperature water boilers shall be provided
						with adequate provisions for water drainage as well as the steam venting. The
						installation of cast iron bodied safety relief valves for high temperature
						water boilers is prohibited.
(4)
						The discharge of safety valves or safety relief valves shall be located so as
						to prevent scalding.