N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 14-10.16
Safety valve or valves shall be placed as close to the boiler as possible. No valve of any description shall be placed between the safety valve and the boiler, nor on the discharge pipe between the safety valve and the atmosphere. When a discharge pipe is used, it shall be not less than the full size of the valve, and the discharge pipe shall be fitted with an open drain to prevent water lodging in the upper part of the safety valve or in the pipe. If a muffler is used on a safety valve it shall have sufficient outlet area to prevent back pressure from interfering with the proper operation and discharge capacity of the valve. The muffler plates or other devices shall be so constructed as to avoid any possibility of restriction of the steam passages due to deposit. When an elbow is placed on a safety-valve discharge pipe, it shall be located close to the safety-valve outlet or the pipe shall be securely anchored and supported. All safety-valve discharges shall be so located or piped as to be carried clear from running boards or working platforms used in controlling the main stop valves of boilers or steam headers.
N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 14-10.16