BACK VALVE WITH AXIAL DIRECTION OF FLOW (VERSIONS) Russian patent published in 2011 - IPC F16K15/06 

FIELD: machine building.

SUBSTANCE: back valve consists of external case with inlet and outlet channels. A circular seat, contacting the seat shut-off spring-loaded element with a double-sided rod, and rigidly fastened fairing are arranged in an internal cavity of the case forming a circular channel of a Venturi nozzle-like profile. The rod travels in two bushings fixed in the seat and along axis of the fairing with webbing. The seat is divided into two parts: an external one - with power thread, and internal one rigidly fixed with a thrust ring. This ring is positioned in a circular slot formed with contact surfaces of the external and internal parts of the seat and with a boring on internal surface of the external case. Contact surfaces of the thrust ring and the external part of the seat are conic. The thrust ring is divided into parts along lines parallel to diametre of circumference of ring section. A centring bushing of the rod of the shut-off element is installed in an additional fairing from the side of the inlet channel. The additional fairing is fixed in the seat with webbing. The centring bushing is equipped with a protective movable cylinder. The cylinder is secured in external spherical working surface of the shut-off element. Ends of the centring bushings of the rod are equipped with protective removable plugs. There is claimed the version of design of the back valve.

EFFECT: increased reliability by facilitating stable pressure tightness through whole service life of back valves; their increased repair ability.

5 cl, 5 dwg