ASTM D4692 - 01(2026)

1.1 This practice covers the calculation and adjustment of calcium, strontium, and barium sulfates for the concentrate stream of a reverse osmosis or nanofiltration system. The calculations are used to determine the need for scale control in the operation and design of reverse osmosis and nanofiltration installations. This practice is applicable for all types of reverse osmosis devices (tubular, spiral wound, and hollow fiber) and nanofiltration devices.

1.2 This practice is applicable to both brackish waters and seawaters.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.