Section 56(5) in The West Bengal Factories Rules, 1958
(5)(a)Every pressure vessel which is designed for a working pressure less than the pressure at the source of supply, or less than the pressure which can be obtained in the pipe connecting the pressure vessel with any other source or supply, shall be fitted with a suitable pressure reducing valve or other suitable automatic device to prevent the maximum permissible working pressure of the pressure vessel being exceeded.(b)To further protect the pressure vessel in the event of failure of the reducing valve or device, at least one suitable safety valve or other pressure, relieving device of adequate capacity sufficient to release of the steam, vapour or gas without undue pressure rise as determined by the pressure at the source of supply and the size of the pipe connecting the source of supply, shall be fitted close to the reducing valve on the low pressure side.
