BS 1868:1975+A1:1990

BS 1868:1975+A1:1990 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 (see Figure 1);

b) lift:

i) piston type, for angle or horizontal flow (see Figure 2);

ii) ball type, for angle or horizontal flow (see Figure 3);

iii) ball type, for vertical flow (see Figure 4);

iv) disk type, for vertical flow (see Figure 5).

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.

Nominal sizes, ratings, design, materials, marking and shipping for swing, piston, ball and disk valves for Class 150 up to Class 2500 and of nominal sizes 15 to 600 mm. Appendix for application to piping systems with BS 4504:Part 1.

Cross References:
BS 1133-6
BS 1400
BS 1501-1506
BS 1503
BS 1560-2
BS 1600-2
BS 1832
BS 2080
BS 2872
BS 2874
BS 3071
BS 3076
BS 3351
BS 4504-1
BS 4882
BS 6755-1


Incorporates the following:
AMD 6563 published 31 July 1990
Amends and replaces BS 1868:1975. Corrigendum, January 2010