ISO 16784-2:2006

Overview

ISO 16784-2:2006 - Corrosion of metals and alloys: Corrosion and fouling in industrial cooling water systems - Part 2 - defines a laboratory and pilot-scale method to evaluate the performance of cooling water treatment programmes using a pilot-scale test rig (heat-exchanger/heat-transfer tubes). The standard applies to open recirculating cooling water systems and is intended for preliminary screening of inhibitors, biocides and other treatment regimes. Note: it does not cover heat exchangers with cooling water on the shell side.

Key topics and requirements

• Scope and principle: describes a pilot-scale test assembly where metallic test tubes are exposed to circulating cooling water under controlled heat-transfer conditions to assess corrosion and fouling.
• Test waters: guidelines for using on-site make-up water or synthetic test water prepared from mother (stock) solutions; synthetic waters are acceptable for comparative screening but may be more aggressive than natural waters.
• Water characterization: specifies parameters to record (pH, conductivity, hardness, alkalinity, Ca2+, Mg2+, Cl–, SO4 2–, TOC, silica, turbidity, bacteria, ATP, etc.) for both make-up and circulating water.
• Apparatus and operation: test rig components include heat-transfer tubes, pump, flow control, temperature measurement, blow-down and make-up monitoring, and optionally a pilot cooling tower for evaporation/concentration.
• Test procedures: cleaning and preparation of test tubes, filling procedures, heating, controlled flow rates, cycles of concentration, blow-down/half-life determination, and biocide treatment regimens.
• Measurements and assessment: methods for quantifying deposition/fouling and corrosion (tube treatment, analytical controls), recording cooling water quality, and reporting test results.
• Reporting: required test data sheets and annexes (informative) to ensure consistent documentation and comparison of treatment performance.

Applications and users

ISO 16784-2 is practical for:

• Corrosion and water treatment engineers evaluating inhibitors, scale control and biocides.
• Cooling system operators and facility managers wanting pilot verification before full-scale changes.
• Water treatment vendors performing comparative screening of treatment programmes.
• Laboratories and on-site R&D teams conducting controlled pilot-scale performance tests or on-site evaluations of heat exchangers.

Benefits include more consistent, comparable screening of cooling water treatment options and improved decision-making for corrosion and fouling control in industrial cooling systems.

Related standards

• ISO 16784-1 (Guidelines for pilot-scale evaluation)
• Normative references cited: ISO 3696, ISO 8407, ISO 8501-1, ISO 11463

Keywords: ISO 16784-2, corrosion, fouling, industrial cooling water systems, pilot-scale test rig, cooling water treatment, heat exchanger testing, open recirculating cooling water, synthetic test water, cycles of concentration.