Application The butterfly swing check valves are self-acting
and fast-closing valves which prevent a  working medium from flowing back
in a  pipeline. They are used in order to prevent from backflow the pumps,
fans etc. The check valve is not a shut-off valve. Working medium Water,
air, steam and other non-aggressive liquids and gases. The fluid flow direction
may be only from one side of the valve. The fluid flow direction is marked with
an arrow on the valve body. Working temperature Service temperature depends on
the material of seals. - 46°C up to 300 °C Technical description The valve
disc, eccentrically embedded, rotates inside a  flanged end fabricated
body. The shaft is clamped in the self-lubricated friction bearings. Outside
the valve on the end of the shaft there is the lever with counterweight.
Operation The swing check valves are automatic, quick-acting valves. Movement
of the disc is controlled by the flowing fluid. Testing The butterfly swing
check valves are tested for strength and leakage, functionality and tightness
acc. to EN 12 266 section 1, leakage grade is D (grade B on request) or
acc. to API 598. Connection to piping flanged ends acc. to EN 1092-1, EN 1759-1
or GOST 12815-80 face to face dimension acc. to EN 558 welded ends acc. to EN
12 627 face to face dimension acc. to EN 12 982