N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 14-9.17

Current through Register Vol. 46, No. 53, December 31, 2024

Section 14-9.17 - Shutoff valves

(a)

(1) Each water-gage glass shall be equipped with a top and a bottom shutoff valve of such through-flow construction as to prevent stoppage by deposits of sediments. If the lowest valve is more than seven feet above the floor or platform from which it is operated, the operating mechanism shall indicate by its position whether the valve is open or closed. The pressure-temperature rating shall be at least equal to that of the lowest set pressure of any safety valve on the boiler drum and the corresponding saturated steam temperature.

(2) Straight-run globe valves of the ordinary type as shown in Figure P-43(a) shall not be used on such connections.

(3) Automatic shutoff valves on water gages, shall conform to the following requirements:

(i) check valves in upper and lower fittings shall be of solid noncorrosive metal ball type to avoid need for guides;

(ii) ball check valves in upper and lower fittings must open by gravity and the lower ball check valve must rise vertically to its seat;

(iii) the check balls must be not smaller than 1/2 inch in diameter, and the diameter of the circle of contact with the seat must be not greater than two-thirds of the diameter of the check ball. The space around each ball must be not less than 1/8 inch, and the travel movement from the normal resting place to the seat must be not less than 1/4 inch;

(iv) the ball seat in the upper fitting must be a flat seat with either a square or a hexagonal opening, or otherwise arranged so that the steam passage can never be completely closed by this valve;

(v) the shutoff valve in the upper fitting must have a projection which holds the ball at least 1/4 inch away from its seat when the shutoff valve is closed; and

(vi) the balls must be accessible for inspection. Means must be provided for removal and inspection of the lower ball check valve while the boiler is under steam pressure. These restrictions do not apply to closing the valves by external methods.

(b) When shutoffs are used on the connections to a water column, they shall be either outside-screw-and-yoke or lever-lifting type gate valves or stopcocks with levers permanently fastened thereto and marked in line with their passage, or of such other through-blow construction as to prevent stoppage by deposits of sediment, and to indicate by the position of the operating mechanism whether they are in open or closed position; and such valves or cocks shall be locked or sealed open. Where stopcocks are used they shall be of a type with the plug held in place by a guard or gland.

N.Y. Comp. Codes R. & Regs. Tit. 12 §§ 14-9.17