Interpretation Response #PI-21-0009
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: CH-IV
Individual Name: Mr. Juan Carlos Rivadeneira
Location State: TX Country: US
View the Interpretation Document
Response text:
Mr. Juan Carlos Rivadeneira
Engineer
CH-IV
1221 McKinney, Suite 3333
Houston, TX 77010
Dear Mr. Rivadeneira:
In a letter to the Pipeline and Hazardous Materials Safety Administration (PHMSA), dated August 19, 2021, you requested an interpretation of the minimum pipeline welding inspection and testing requirements for piping systems and components for flammable liquids and flammable gases with service temperatures above −20 degrees Fahrenheit (°F) (−29 °Centigrade (C)) to comply with 49 Code of Federal Regulations (CFR) § 193.2303. Specifically, you sought confirmation that for these piping systems and components to comply with § 193.2303, a minimum of 30 percent of each day's circumferentially welded pipe joints must be nondestructively tested over the entire circumference.
Section 193.2303 incorporates by reference the 2001 edition of National Fire Protection Association Standard 59A (NFPA 59A-2001), and Chapter 6 of NFPA 59A-2001 specifies requirements for piping systems and components. While paragraph 6.1.1 of NFPA 59A-2001 requires that all piping systems comply with the 1996 Edition of ASME B31.3, it further states that the additional provisions of Chapter 6 of NFPA 59A-2001 shall apply to piping systems and components for flammable liquids and flammable gases with service temperatures below −20 °F (−29 °C). The provision found in paragraph 6.6.3.2 of NFPA 59A-2001, which requires that all circumferential butt welds be examined fully by radiographic or ultrasonic inspection, contains an exception for pressure piping operating above −20 °F (−29 °C). Specifically, Exception No. 2 to paragraph 6.6.3.2 states:
Pressure piping operating above −20 °F (−29 °C) shall have 30 percent of each day's circumferentially welded pipe joints nondestructively tested over the entire circumference in accordance with ASME B31.3.
Moreover, paragraph 341.4.1(b)(1) of ASME B31.3 requires that not less than 5 percent of circumferential butt and miter groove welds be examined fully by random radiography in accordance with paragraph 344.5 or by random ultrasonic examination in accordance with paragraph 344.6. However, performing a minimum of 5 percent of examination per ASME B31.3 does not meet the requirements in NFPA 59A-2001. Instead, an operator shall have 30 percent testing for each day's circumferentially welded pipe joints in accordance with NFPA 59A-2001.
Therefore, PHMSA agrees with your interpretation of the NFPA 59A-2001 requirements that for flammable liquids and flammable gases with service temperatures above −20 °F (−29 °C) to comply with § 193.2303, a minimum of 30 percent of each day's circumferentially welded pipe joints must be nondestructively tested over the entire circumference.
If we can be of further assistance, please contact Tewabe Asebe at 202-366-5523.
Sincerely,
John A. Gale
Director, Office of Standards
and Rulemaking
Regulation Sections
| Section | Subject |
|---|---|
| 193.2303 | Construction acceptance |