Date of Issue: May 2017
Affected Publication: API 570, Piping Inspection Code: In-service Inspection, Rating, Repair,
and Alteration of Piping Systems, Fourth Edition, February 2016
Addendum 1
Page 31, Section 5.6.2, second paragraph, last sentence, shall read:
For systemized/circuitized piping, the corrosion rates and remaining life may be determined
statistically per paragraph 6.5.3.
Page 33, Section 5.7.1, first paragraph, fifth sentence, shall read:
Ultrasonic thickness measurements taken on small bore pipe may require specialized
equipment (e.g. miniature transducers and/or curved shoes as well as diameter-specific
calibration blocks); however, Profile RT is typically the method of choice for thickness
measurements on small bore piping.
Page 41, Section 5.13, fourth paragraph, second sentence, shall read:
Critical check valves shall be adequately inspected or tested to provide greater assurance
that they will prevent flow reversals.
Page 46, Section 6.3.4.1, first paragraph, last sentence, shall read:
When pipe service conditions change, pipe classifications and inspection plans should be
reviewed and updated as necessary to reflect the changed operating conditions; e.g. a
hydrocarbon service temperature increase that might change from “slowly vaporizing during
a release” to “rapidly vaporizing during a release.”
Page 46, Section 6.3.4.2e, shall read:
Hydrofluoric acid in main and trace acid services per API RP 751.
Page 54, Section 7.1.2, second equation (Short term corrosion rate), shall read: