Specification for Steel check valves (flanged and butt-welding ends) for the petroleum, petrochemical and allied industries BS 1868:1975

Specification for
Steel check valves
(flanged and
butt-welding ends) for
the petroleum,
petrochemical and
allied industries
BS 1868:1975


This British Standard specifies requirements for cast or forged steel check valves with flanged or
butt-welding ends of the following types:
a) swing, for vertical or horizontal flow 
b) lift:
i) piston type, for angle or horizontal flow 
ii) ball type, for angle or horizontal flow 
iii) ball type, for vertical flow
iv) disk type, for vertical flow 
The terms “vertical”, “horizontal” and “angle” relate to the axes of the body ends.
When swing check valves are used in vertical lines the flow must be in an upward direction. For the
purposes of this standard any line with a slope (upward or downward) of 5° or less is deemed to be
horizontal. In the case of angle pattern valves the inlet should be vertical.

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