Overview
ISO 15748-2:2002 is an international standard developed by the International Organization for Standardization (ISO) focusing on ships and marine technology, specifically the potable water supply on ships and marine structures. This document, Part 2: Method of Calculation, provides guidelines for the calculation and sizing of potable water supply systems for ships, stationary or floating marine structures, and inland waterway crafts. The standard outlines methods to determine the required quantity of potable water, the capacity of pressurized reservoirs and water heaters, and the pumping capacity necessary to ensure safe, reliable, and efficient potable water supply on board.
Key Topics
ISO 15748-2 covers the following important topics relevant for marine potable water systems:
- Potable Water Consumption: Guidance on estimating daily water requirements based on vessel type, crew and passenger numbers, duration at sea, and service points (such as washbasins, showers, toilets, and commissary equipment).
- Potable Water Storage: Considerations for storage and, where relevant, water distillation plants in consultation with contractors.
- System Component Sizing: Methods for determining the size of system components taking into account piping material, installation configuration, and expected peak flow rates.
- Flow Rates and Pressure: Specified limits for flow rates in various vessel locations to avoid noise and pressure surges, and calculation of minimum and working supply pressures.
- Pump Sizing and Reservoirs: Criteria for selecting and sizing supply pumps and pressurized water reservoirs, including cut-in and cut-off pressure differences and switching frequency.
- Pipe Sizing: Procedures for determining the required nominal pipe diameters based on calculated flow rates and distribution system layout.
- Hot Water Requirements: Determination of hot water demands, sizing of water heaters (continuous-flow or storage), and setup of circulation lines.
- Calculation Tools: Reference to tables, figures, and annexes that provide supporting data, nomograms, and calculation forms for practical implementation.
Applications
ISO 15748-2:2002 is a key resource during the planning and design phases of potable water supply systems on vessels and marine structures. Its applications include:
- New vessel and structure projects: Ensures safe, adequate potable water supply by providing a standardized method for calculations during the design phase.
- Retrofits and Upgrades: Assists shipyards and marine engineers when upgrading or replacing potable water systems, ensuring capacity and safety compliance.
- Regulatory Compliance: Helps demonstrate compliance with classification society requirements and international maritime health and safety regulations.
- Operational Planning: Used by ship operators and facility managers to assess potable water needs for varying passenger and crew levels, voyage duration, and operational scenarios.
- Component Specification: Serves as a guide to specify and select appropriate tanks, pumps, heaters, and piping to minimize operational risks such as water shortages or mechanical failures.
Related Standards
Understanding and applying ISO 15748-2 is enhanced when used alongside other relevant standards, including:
- ISO 15748-1: Ships and marine technology - Potable water supply on ships and marine structures - Part 1: Planning and design
- ISO 65: Carbon steel tubes suitable for screwing in accordance with ISO 7-1
- ISO 161-1: Thermoplastics pipes for the conveyance of fluids - Nominal outside diameters and nominal pressures - Part 1: Metric series
- ISO 274: Copper tubes of circular section - Dimensions
- ISO 1127: Stainless steel tubes - Dimensions, tolerances, and conventional masses per unit length
- ISO 4200: Plain end steel tubes, welded and seamless - General tables of dimensions and masses per unit length
- ISO 5620-1: Shipbuilding and marine structures - Filling connection for drinking water tanks - Part 1: General requirements
By following the methods and recommendations in ISO 15748-2:2002, stakeholders in shipbuilding, marine engineering, and onboard facility management can ensure the health, safety, and comfort of vessel occupants, as well as optimize the reliability and performance of potable water supply systems in marine environments.