Section 2 System construction and installation

2.1.1 Pipes, valves and fittings are, in general, to be made of steel, ductile cast iron, copper, copper alloy, or other approved ductile material suitable for the intended purpose. The use of plastics materials is also acceptable subject to any restrictions in Vol 2, Pt 7, Ch 1 Piping Design Requirements.

2.1.2 Where applicable, the materials are to comply with the requirements of Vol 2, Pt 7, Ch 1 Piping Design Requirements.

2.1.3 The selection of materials in piping systems is to recognise the following details:

1. Fluid properties, pressures and temperatures.

2. Location and configuration.

3. Compatibility of materials.

4. Fluid flow rates and static conditions.

5. Minimising corrosion and erosion through life of system.

6. System survey, cleaning and maintenance requirements.

See Vol 2, Pt 7, Ch 1, 17 Guidance notes on metal pipes for water service for guidance notes on metal pipes for water services.

2.1.4 Materials for use in fresh water systems for use of crew and embarked personnel and for food preparation are to be of types that do not provide a habitat for bacteria which can occur with natural rubber, various plastics and fibre accessories, and do not leach out toxic constituents.

2.2.1 The minimum nominal wall thickness of steel, copper and copper alloy pipes are to be in accordance with Vol 2, Pt 7, Ch 1 Piping Design Requirements.

2.2.2 Special consideration will be given to the wall thickness of pipes made of materials other than steel, copper and copper alloy.

2.3.1 Pressurised tanks are to be in accordance with the requirements of Vol 2, Pt 8, Ch 2 Other Pressure Vessels.

2.3.2  Valves, flexible hose lengths, expansion pieces and pumps are to comply with the relevant requirements of Vol 2, Pt 7, Ch 1, 12 Valves to Vol 2, Pt 7, Ch 1, 15 Pumps, (see also Vol 2, Pt 11, Ch 1, 2.1 Materials regarding selection of materials). The configuration of piping systems is to be arranged to minimise erosion and corrosion of pipe and equipment materials. Equipment used in made and fresh water systems and piping systems is to be suitable for its intended purpose, and accordingly, wherever practicable, be selected from the Lists of LR Type Approved Products published by LR.

2.3.3 Pipes in piping systems are to be permanent pipes made with approved pipe connections to enable ready removal of valves, pumps, fittings and equipment. The pipes are to be efficiently secured in position to prevent chafing or lateral movement.

2.3.4 Suitable means for expansion is to be made, where necessary, in each range of pipes.

2.3.5 Efficient protection is to be provided for all pipes situated where they are liable to mechanical damage.

2.3.6 All moving parts are to be provided with guards to minimise danger to personnel.

2.4.1 Valves are to be fitted in places where they are at all times readily accessible.

2.4.2 All valves that are provided with remote control arrangements are to be arranged for local manual operation, independent of the remote operating mechanism. The local manual means of operation is to be readily accessible.

2.4.3 Relief valves are to be adjusted and bursting disks so selected that they relieve at a pressure not greater than the design pressure of the system. When satisfactorily adjusted, relief valves are to be protected against tampering or interference by wire with a lead seal or similar arrangement.

2.5.1 Sacrificial anode cathodic protection is not permitted in made and fresh water storage tanks.

2.6.1 Storage tanks, piping and valves constructed from carbon and low alloy steels and cast irons are to be lined internally with a corrosion control coating suitable for the containment and transfer of made and fresh water.

2.6.2 Corrosion control coatings are to be tested and certified as complying with standards specified by the Designer and Owner.

2.7.1 Subject to compliance with Vol 2, Pt 7, Ch 1, 11 Plastic pipes and Vol 2, Pt 7, Ch 1, 13 Flexible hoses, and the relevant Sections of Vol 2, Pt 7, Ch 2 Ship Piping Systems, plastic piping which is internally uncoated may be used in piping systems for made and fresh water.

2.7.2 Any internally uncoated plastic piping or flexible hose in contact with made or fresh water is to be suitable for the containment and transfer of made and fresh water.

2.7.3 Uncoated plastic piping and flexible hoses are to be tested and certified as complying with current standards for use in made and fresh water systems.

2.7.4 Plastic piping is to be selected in consultation with the manufacturers with regard to suitability with the proposed pipe system cleaning practice.