Each manifold arm shall be fabricated in such a way that minimum joints are provided. Only seamless pipes are recommended for use in manifolds. There should be a minimum gap of 300 mm between the manifold and valve protection ring of the LPG cylinders.

Note: Maintaining a 300 mm gap, as specified in IS 6044 Part 1, may not be practical for 425 kg cylinders. Given their height of 1865 mm, this requirement results in a total height that exceeds 2 metres, potentially hindering effective access and operation of the manifold’s ball valves.

The individual component parts of manifolds, that is, piping, fittings, flexible hoses etc, which are subject to cylinder pressure shall be capable of withstanding a test pressure of 25 kgf/cm2 or 1.5 times the developed pressure at 65°C, whichever is more, without bursting. Rubber hoses used shall confirm to IS 9573 (Part 1).

A minimum distance of 400 mm shall be maintained between two nipples provided on the manifold for connecting the cylinders to the manifold. In case of staggered arrangement of cylinders, a minimum distance of 150 mm shall be maintained between two nipples provided on the manifold.

In case, the diameter of the cylinder is higher than 400 mm, then the minimum distance between the two nipples shall be diameter of the cylinder plus 100 mm.

A pressure gauge of minimum dial size of 10 cm shall be provided in the manifold to indicate the gas pressure in the manifold. The pressure gauge shall be suitable for a pressure range 0 to 30 kgf/cm2.

Note: Requirement for LPG as per IS 4576:2021 mentions Vapour (gauge) pressure at 40°C shall not be more than 1050 kPa (10.5 bar). In any case the minimum for the mixture shall be not lower than 520 kPa (5.20 bar) at 40°C, so it is preferred to use a gauge with a pressure range of 0 to 21 bar which is double gauge pressure at 40°C allowed by IS 4576:2021.