Section 34(2) in The Merchant Shipping (Fire Appliances) Rules, 1969
(2)The diameter of the fire main and water service pipes shall be sufficient for the effective distribution of the maximum required discharge from one or two fire pumps as required to be provided by the rules operating simultaneously except that in the case of cargo ships the diameter need only be sufficient for the discharge of 140 tonnes per hour. The fire mains shall have no connection other than those necessary for fire fighting and washing down.
