Section
2 Equipment and components
2.1 Materials
2.1.4 Materials for fresh water systems for potable water 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, see also ISO
15748-1.
2.2 Pipe wall thickness
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 Piping and equipment
2.3.2 Valves, flexible hoses, expansion pieces and pumps are to comply with
Pt 5, Ch 26, 2.1 Materials and the following
requirements:
- Valves - Pt 5, Ch 12, 6 Valves
of the Rules and Regulations for the Classification of Ships, July 2022.
- Flexible hoses - Pt 5, Ch 12, 7 Flexible hosesFlexible hoses of the Rules and Regulations for the Classification of Ships, July 2022.
- Expansion pieces - Pt 5, Ch 12, 2 Expansion pieces.
- Pumps - Pt 5, Ch 26, 2.6 Pumps.
2.3.3 The configuration of piping systems is to be arranged to minimise erosion and
corrosion of pipe and equipment materials. Equipment used in fresh water systems and
piping systems is to be suitable for its intended purpose, and accordingly, wherever
practicable, be selected from LR’s List of Type Approved Products.
2.3.4 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.
2.3.5 Suitable means for expansion is to be made, where necessary, in the piping
system.
2.3.6 Efficient protection is to be provided for all pipes situated where they are liable
to mechanical damage.
2.4 Valves and bursting disks
2.4.1 Valves are to be fitted in places where they are readily accessible at all times.
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 selected so 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 Expansion pieces
2.5.1 The design and construction of expansion pieces intended for installation in piping
systems is to be in accordance with Pt 5, Ch 12, 2 Expansion pieces.
2.6 Pumps
2.6.1 Pumps are to be capable of operating satisfactorily under the conditions
shown in Pt 5, Ch 1, 2 Operating conditions. The selection of
pumps is to consider:
- Pump characteristic and required duty.
- Performance if required to perform a secondary duty.
- Pumped fluid and its temperature ranges.
- Maximum discharge pressure head from the pump and design
pressure of piping system.
- The size of air pipes and capacity of air pipe heads fitted to
tanks which can be pumped up.
- The need to fit relief devices to pumps and piping systems.
- Maximum permissible fluid velocities in the piping system to
avoid erosion and damage to valve seats and other fittings, see also
Pt 5, Ch 12, 11.6 Water velocity of the Rules and Regulations for the Classification of Ships, July 2022.
- Minimum fluid velocities to avoid fouling and subsequent
pitting, see also
Pt 5, Ch 12, 11.6 Water velocity of the Rules and Regulations for the Classification of Ships, July 2022.
2.7 Cathodic protection
2.7.1 Sacrificial anode cathodic protection is not permitted in fresh water
storage tanks.
2.8 Coating of storage tanks and piping internal surfaces
2.8.1 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 fresh water.
2.8.2 Corrosion control coatings are to be tested and certified as complying with standards
specified by the designer and Owner.
2.9 Plastic piping and flexible hoses
2.9.1 Plastic piping which is internally uncoated may be used in piping systems for fresh
water, subject to compliance with;
2.9.2 Any internally uncoated plastic piping or flexible hose in contact with fresh water
is to be suitable for the containment and transfer of fresh water in accordance with
a recognised National or International Standard e.g. BS 6920-1 Suitability of
non-metallic materials and products for use in contact with water intended for
human consumption with regard to their effect on the quality of the
water.
2.9.3 Uncoated plastics piping and flexible hoses are to be tested and certified as
complying with current standards for use in fresh water systems.
2.9.4 Plastic piping is to be selected in consultation with the manufacturers with regard
to suitability with the proposed pipe system cleaning practice.
2.10 Direct steam water calorifiers
2.10.1 Steam used directly to heat potable water, e.g. in direct steam injection heaters, is
to be suitable for potable use.
2.10.2 Feedwater and boiler water in a boiler supplying steam to heat potable water are to
be treated in accordance with a recognised National or International Standard e.g.
BS 2486 Recommendations for treatment of water for steam boilers and water
heaters and BS EN 12953-10 Shell boilers. Requirements for feedwater and
boiler water quality.
2.10.3 All chemicals used to treat the boiler feed water e.g. to inhibit scale formation,
corrosion, freezing and sludge in a boiler supplying steam to heat potable water are
to be approved for use with potable water in accordance with a recognised National
or International Standard e.g. NSF/ANSI 60 - Drinking Water Treatment Chemicals –
Health Effects.
2.10.4 Filling pipes used for adding chemicals are to have close-fitting caps to prevent
ingress of a contaminant/foreign matter.
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