Marine piping systems

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Pipe Design and Production

Ship Piping Systems

Marine Piping Systems

Bilge System

• Basic requirement is to provide effective drainage to all dry spaces and at the same time prevent water from entering the spaces through this system.

• Discharge of oily water from machinery spaces is to comply with MARPOL Annex 1

• Oily water is treated in an oily-water separator before being allowed to be discharged.

• Discharge water must be monitored with purity not to exceed ppm set by MARPOL.

Bilge System

Bilge main diameter, dm

25)(68.1 DBLdm

L = length of ship

B = Breadth

D = Depth

25)(15.2 DBldb

Branch bilge main diameter, db

l = length of compartment

Bilge System

Bilge pump capacity, Q

1075.5 mdQ

• Two bilge pumps are required• Suctions are arranged such that water can be

pumped out when ship is inclined 5°• Arrangement must be such that water cannot pass

from sea or ballast system into dry spaces through the bilge system

(m3/h)

Oily-water Separator

Ballast System

• For safe operation, at least two ballast pumps are to be connected to ballast tanks.

• Stripping eductor can also be used for emptying the bilges in cargo holds with 2 non-return valves between hold and system

• Ship side valve material must not of grey cast iron and to direct mechanical manual operate

Air and Sounding Systems

Purposes• to secure ventilation of tanks, cofferdam and

tunnels to prevent over-pressurizing and vacuum (air pipes)

• to ascertain the level of liquid in tanks, cofferdam and tunnels (Sounding pipes)

• Vent pipes need to prevent flooding of spaces through their upper ends

• Vent pipes need to safely prevent flammable liquids or vapours due to their fire hazards

Machinery Spaces• Heavy fuel oil overflow tank has short self-closing

type sounding pipe• HFO overflow tank air pipe is led to open deck as

required.• Lubricating oil sump tank air pipe may end inside

machinery space but away from ignition sources

Machinery Spaces• Air or overflow pipes internal are are normally

required to be 1.25 times the area of respective filling pipes for a tank.

• Velocity in the air pipe is not to exceed 4 m/s when using one pump for one tank.

Fire-Fighting SystemsFire-fighting System

Fire-Fighting Systems

Three groups:• Fire Main

– Seawater as fire extinguishing medium

– At least two fire pumps and are located in two different compartments

– An international shore connection is provided at port and starboard for external water supply

– System is tested with at least streams of water directed from one fire pump.

– Pressure relief valve is fitted to mains to protect sudden over-pressure.

Three groups:• Carbon Dioxide system

– Dry fire protection

– Used in compartments that have potential for fire: engine room, emergency generator room, paint locker and galley hood

– System is equipped with audio and visual alarm to alert personnel to evacuate

– Prior to CO2 release, ventilation fans and fire damper to be shut.

Three groups:• Sprinkle system

– Wet fire protection mainly for accommodation area– System is filled with fresh water and pressurized by

compressed air– Subsequently, water is supplied from fire main– Sprinkle and fire main systems are separated by an

alarm check valve.– When the pressure in the sprinkle drops below the fire

main fire pressure, the fire main pressure will overcome the internal pressure of the valve lift and automatically push open to accommodate the fire main.

Fuel Oil Systems

Main concerns• Fire hazards

– Flash point

– Insulation

– Remote control of fuel oil valves

– Stopping of pumps

– Collection of drains from leaks

• Materials– Fuel oil pipes and their valves and fittings is required to

be of steel or other fire-resistance materials

FO Storage and Transfer

Important concerns• Overflow pipes• Quick-closing valves• Drain to waste oil tanks (spill trays)• Level gauge with heat-resistant glass for sounding• Remote control of fuel oil valves• Insulation of hot surfaces where fuel oil leaks

(possibly in a spray form) is possible

HFO Settling Tank

HFO Service Tank

Quick-closing Valves

FO Supply to Engine

FO System

FO Supply to Engine

Main components• Storage (bunkers)• Transfer pump• Settling tank• Heater• Purifier• Service tank• Filter• Viscosity controller• Return Tank (10 to 15 minutes engine operation)

HFO Duplex Filter

HFO Transfer Pump

HFO Heater

HFO Separator

HFO Separation System

Diesel Fuel Separation System

Lubricating Oil Storage and Transfer

Main components• Filling from deck to tanks• Main LO storage tank to deliver to ME sump tank• Quick-closing valves operable from outside ER

where valves are below top of tanks (not applicable for small tanks below 0.5 m3)

• Air pipes may terminate inside ER provided their openings do not constitute a fire hazard

• Duplex filters (or self-cleaning) are used without interrupting operations

Lubricating Oil Circulation System

Lubricating Oil Service Tank

Lubricating Oil Pump

Lubricating Oil Filter – Self-cleaning

Lubricating Oil System - Thermostatic Valve

Shell-and-Tube LO Cooler

Lubricating Oil Purifier

Seawater Cooling System

Arrangement• Conventional and Central cooling• High and low sea chests• Suctions are arranged from two sea inlets

preferably on the opposite sides of the ships• Filters can be cleaned without interrupting the

water supply in the system.• Temperature controlled three-way valves to re-

circulate water when the water is cold

Seawater Cooling System

Overboard Discharge

Freshwater Cooling System Freshwater Cooling System

Freshwater Cooling System

Arrangement• Freshwater from engine is delivered to freshwater

generator (evaporator)• Pressure in the system is regulated by he

expansion tank• Temperature-controlled three-way valves to allow

re-circulation• High-temperature circuit (jacket cooler), low-

temperature circuit (lubricating oil)

Freshwater Generator (Evaporator)

Freshwater Cooler (Plate-type)

Jacket Water Pump

Freshwater Header Tank

Compressed Air System

• Normally three systems

– Starting air

– Service air

– Control air

• Require two main compressors to charge two air receivers from atmospheric within one hour

• Capacity of receivers sufficient to produce:– 12 starts for reversible engines

– 6 starts for non-reversible engines

– 3 starts for auxiliary engines

Compressed Air System

• No connections to other machinery between air

compressors and main air receivers• Emergency air compressor can be diesel driven or

power supplied from emergency generator• Pressure reduction stations and filters are required

to be duplicates• Safety relief valves are fitted at receivers and set

at 10% above operating pressure• Compressed air line is classes as Class II due to

high pressure.

Air Compressors

Air Receivers

Auxiliary Air Receiver

Emergency Air Receiver

Control Air Dryer (Refrigerant-type)

Pressure-reducing Station

Domestic Water System

• Freshwater is made by Freshwater generator (evaporator)

• Delivery of water to accommodation from hydrophore units is by compressed air

• Domestic water is sterilized before consumption• Domestic water is heated and then circulated (by

hot-water circulating pumps) • Domestic water is also used by HFO, DO and LO

separators

Hydrophoreunit

Domestic Water Heater

Power Generating System

Generator System Diesel

Generator System

Steam System

• Normally divided into:– Feed water systems

– Steam supply• For heating tanks

• For heating pipelines

• To heat exchangers

– Condensate

• Heat of exhaust gas is recovered in economizer to generate steam

• Diesel propulsion system is normally fitted with an auxiliary boiler

Steam System

• Steam with pressure above 7 bar or temperature above 170°C are considered Class II piping.

• Steam with pressure above 16 bar or temperature above 300°C is of Class I piping.

• With respect to materials for valves and fittings in Class II piping system, grey cast iron may not be used up to ND 200, pressure up to 13 bar and temperature up to 250°C

Auxiliary Boiler

Cargo Pump Turbine and Condenser

Marine piping systems

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