Check valve 3s-6-4

Reverse valves are used in pipeline systems as uncontrolled, automatically acting protective devices, serving to prevent the reverse flow of the working medium in emergency situations.
In working condition the check valve/valve is open under the influence of the working medium flow. In the absence of medium flow or in case of flow in the opposite direction, the valve/valve is closed.
Design versions: lift and butterfly valves.
Installation position of the check valve: only on horizontal pipeline sections with the medium flow direction "under the plate", so that the flow direction coincides with the arrow marked on the body, with the nut (cover) pointing upwards only.
Connection to pipework: under welding.
Gate tightness: according to class A of GOST 9544-2015.
Climatic design: ?, ???, ??, ? according to GOST 15150-69.
Placement category: 1, 2, 3 according to GOST 15150-69. .