Fluid-controlled SISTO-KRVNA valves vent additional safety systems in nuclear power stations.
Fluid-controlled SISTO-KRVNA valves vent additional safety systems in nuclear power stations.

SISTO Armaturen SA, the Luxembourg-based subsidiary of Germany’s KSB SE & Co KGaA, has received a major order to supply special valves for the retrofitting of a number of French nuclear power stations.

The SISTO-KRVNA type valves employ a floating rubber-coated ball that acts as an obturator, reliably venting the discharge lines in the water supply of additional safety systems in nuclear power stations. The vent valve makes sure that the discharge line of the pump automatically fills with water and that any trapped air can escape. It prevents any backflow after the pumps have been stopped and protects the piping from damage caused by low pressure.

SISTO-KRVNA valves do not need dynamic sealing to atmosphere and are designed without any failure-prone components, such as stems. The combination of a stainless steel body and an EPDM-coated steel ball makes for reliable operation with the valve being insensitive to solids-laden and corrosive fluids. The valve is controlled by the fluid, ruling out incorrect operation from the outside.