Section 6 Boiler feed water, condensate and thermal fluid circulation systems

6.1.1 Two separate means of feed are to be provided for all main and auxiliary boilers which are required for Mobility or Ship Type systems. In the case of steam/steam generators, one means of feed will be accepted provided steam for Mobility or Ship Type systems is available simultaneously from another source.

6.2.1 Two or more feed pumps are to be provided of sufficient capacity to supply the boilers under full load conditions with any one pump out of action.

6.2.2 Independent feed pumps required for feeding the main boilers are to be fitted with automatic regulators for controlling their output.

6.2.3 The valves on the suction pipes from the hotwell or condenser and the feed drain tank or filter are to be of the non-return type.

6.2.4 The arrangement of forced water/thermal fluid circulation pumps for exhaust gas economisers/boilers/ thermal heaters is to be such that where required, the flow through the exhaust gas economiser/boiler/thermal heater is to be established prior to engine start up. Where applicable, provision is to be made to allow for operation in the dry condition.

6.2.5 The forced circulation flow required by Vol 2, Pt 7, Ch 3, 6.2 Feed and circulation pumps 6.2.4 is to be maintained on completion of engine shutdown for a sufficient duration in accordance with the exhaust gas economiser/boiler/thermal heater manufacturer’s instructions. Details of arrangements are to be submitted for approval.

6.2.6 Where arrangements are such that exhaust gas economisers/boilers/thermal heaters require forced water /thermal fluid circulation, standby pumps are to be fitted. The standby pump is to start automatically if the discharge pressure from the working pumps falls below a predetermined value.

6.3.1 Two or more extraction pumps are to be provided for dealing with the condensate from the main and auxiliary condensers, at least one of which is to be independently driven. Where one of the independent feed pumps is fitted with direct suctions from the condensers and a discharge to the feed tank, it may be accepted for this purpose.

6.4.1 Feed and condensate pumps are to be provided with valves or cocks, interposed between the pumps and the suction and the discharge pipes, so that any pump may be opened up for overhaul while the others continue in operation.

6.5.1 All ships fitted with boilers are to be provided with storage space for reserve feed water, the structural and piping arrangements being such that this water cannot be contaminated by oil or oily water.

6.5.2 For main boilers, one or more evaporators, of adequate capacity, are also to be provided.

6.6.1 For feed water level regulators for water tube boilers, see Vol 2, Pt 8, Ch 1, 16.8 Feed check valves and water level regulators.