Steel Swing Check Valves GOST R 53672-2009

The valves are used to prevent backflow of the medium in nuclear power plant systems.

The swing check valves are classified as elements of the safety class 2 or 3 acc.to NP 306.2.141. Installation in systems of the safety class 4 is allowed.

Classification designations: 2НO, 3НО, 2НЗ, 3НЗ, 2НОЗ, 3НОЗ.

The swing check valves belong to group B or C according to PNAEG-7-008 (Rules and Norms of Nuclear Power Industry) and have seismic resistance categories I and II, respectively, according to PNAEG-5-006(Rules and Norms of Nuclear Power Industry).

End connection – butt-welded.

The valves can be equipped with disk limit position indicators (Fig. 2).

Sealing surface – corrosion-resistant steel overlay.

Operating medium:

• I – water from the multiple circulation circuit (hereinafter referred to as MCC water), primary circuit coolant, feed water, process water, steam, condensate, distillate, oil, nitrogen, radioactive gases;
• II – boric acid solution (boron content max 16 g/l).

Valve control – automatic, controlled by the medium.

Flow direction – under the disk.

Installation position:

• on a horizontal pipeline – with a slope of no more than 0.004°C, so that the disk axis is in the horizontal plane above the pipeline axis;
• on a vertical pipeline – with the inlet facing down;

on an inclined pipeline – with the inlet facing down, with the disk axis in horizontal position.

The valves shall be installed – in premises being serviced (P), in boxes (B), and under the enclosure (O) of the NPP, in accordance with Table 1.