6.1.1 The
design, construction and operational capability of valves is to be
in accordance with an acceptable National or International Standard
appropriate to the piping system. Where valves are not in accordance
with an acceptable standard, details are to be submitted for consideration.
Where valves are fitted, the requirements of Pt 5, Ch 12, 6.1 Design requirements 6.1.2 are to be satisfied.
6.1.2 Valves
are to be made of steel, cast iron, copper alloy, or other approved
material suitable for the intended purpose.
6.1.3 Valves
having isolation or sealing components sensitive to heat are not to
be used in spaces where leakage or failure caused by fire could result
in fire spread, flooding or the loss of an essential service.
6.1.4 Where
valves are required to be capable of being closed remotely in the
event of fire, the valves, including their controlgear, are to be
of steel construction or of an acceptable fire tested design.
6.1.5 Valves
are to be arranged for clockwise closing and are to be provided with
indicators showing whether they are open or shut unless this is readily
obvious. Legible nameplates are to be fitted.
6.1.6 Valves
are to be so constructed as to prevent the possibility of valve covers
or glands being slackened back or loosened when the valves are operated.
6.1.7 Valves
are to be used within their specified pressure and temperature rating
for all normal operating conditions, and are to be suitable for the
intended purpose.
6.1.8 Valves
intended for submerged installation are to be suitable for both internal
and external media. Spindle sealing is to prevent ingress of external
media at the maximum external pressure head expected in service.