ASTM D2688-23 PDF

Overview

ASTM D2688-23: Standard Test Method for Determination of Corrosion Rate in a Water System in the Absence of Heat Transfer (Weight Loss Method) is an internationally recognized ASTM standard developed to quantify and compare metal corrosion rates in water systems under isothermal conditions. Using weight loss measurements of metallic coupons exposed to flowing water, this test method provides a reliable approach for evaluating the general and localized (pitting) corrosion behaviors of materials commonly used in municipal, industrial, and building piping systems.

Key Benefits:

• Assesses the relative corrosion resistance of various metals
• Compares corrosivity of different water qualities
• Evaluates effectiveness of corrosion inhibitors

Key Topics

• Corrosion Rate Determination: The standard outlines procedures to measure the average and localized (pitting) corrosion of metal specimens (coupons) through weight loss and visual analysis after exposure to water.
• Test Specimen Preparation: Guidelines for preparing, handling, and marking metal coupons consistent with the material used in the water system. Specimens should be fabricated and treated to minimize artifacts from cold-working or surface imperfections.
• Exposure and Flow Conditions: Coupons are mounted in side stream racks to simulate service conditions in piping systems. Flow velocity is carefully regulated to match operational scenarios.
• Types of Corrosion Addressed: Includes uniform corrosion, pitting, crevice corrosion, edge corrosion, and impingement attack. The standard also accounts for the influence of water-formed deposits.
• Data Analysis: Provides formulas for calculating corrosion rate (typically in millimeters per year) and pitting rates, using precise measurements of weight loss and pit depth.
• Quality Control and Sources of Error: Emphasizes specimen consistency, handling, and accurate measurement, and discusses potential errors related to metal composition, flow variation, specimen preparation, and cleaning practices.

Applications

ASTM D2688-23 is widely used across industries where water systems play a critical role. Key applications include:

• Municipal Water Distribution: Assessing the durability of materials and water corrosivity for potable water lines.
• Building and Facility Management: Monitoring corrosion in closed-loop chilled water systems and hydronic heating circuits.
• Industrial Process Water: Evaluating corrosion control strategies in cooling towers, recirculating systems, and plant process water lines.
• Corrosion Inhibitor Evaluation: Testing the effectiveness of chemical additives in mitigating corrosion under controlled water chemistry.
• Maintenance Planning: Informing proactive maintenance and material selection based on comparative corrosion data.

This standard is essential for water treatment professionals, corrosion engineers, facility managers, and manufacturers of piping systems aiming to optimize asset life and reduce unexpected failures.

Related Standards

ASTM D2688-23 references and aligns with several key ASTM standards and guides for corrosion assessment in water systems:

• ASTM G1: Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens
• ASTM G31: Guide for Laboratory Immersion Corrosion Testing of Metals
• ASTM D1129: Terminology Relating to Water
• ASTM D2331: Practices for Preparation and Preliminary Testing of Water-Formed Deposits
• ASTM D2777: Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• ASTM G16: Guide for Applying Statistics to Analysis of Corrosion Data

These companion documents support consistent coupon preparation, data interpretation, and reporting of corrosion rate results, contributing to reliable water system management and regulatory compliance.

Keywords: corrosion rate, water system corrosion, ASTM D2688-23, weight loss method, corrosion coupons, cooling water, building water systems, industrial piping, water quality, corrosion control, pitting corrosion, corrosion inhibition.