N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 14-9.12

Current through Register Vol. 46, No. 51, December 18, 2024

Section 14-9.12 - Blowdown adjustment

(a) Safety valves shall be designed and constructed to operate without chattering and to attain full lift at a pressure no greater than 3 percent above their set pressure. After blowing down, all valves shall close at a pressure not lower than 96 percent of their set pressure, except that all drum valves installed on a single boiler may be set to reseat at a pressure not lower than 96 percent of the set pressure of the lowest set drum valve. The minimum blowdown for spring-loaded safety or safety relief valves shall be 2 percent of the set pressure. Safety valves used on forced-flow steam generators with no fixed steam and waterline, and safety relief valves used on high-temperature water boilers, may be set and adjusted to close after blowing down not more than 10 percent of the set pressure. The valves for these special uses must be so adjusted and marked by the manufacturer.

(b) The blowdown adjustment shall be made and sealed by the manufacturer.

(c) The popping point tolerance plus or minus shall not exceed the following: two pounds for pressures up to and including 70 pounds, three percent for pressures from 71 to 300 pounds and 10 pounds for pressures from 301 to 1000 pounds, and one percent for pressures over 1000 pounds.

N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 14-9.12