Back in January 2019, I posted an article titled “Is API 570 your Piping Inspection/Repair RAGAGEP… Repair Requirements are now crystal clear” and this posting caused quite the stir with many of you. Most of you followed the code(s) and went and verified what I shared in the article, but as usual, I got a lot of negative “feedback” as if I were trying to sell my piping inspection services – the problem is SAFTENG does not offer piping inspection services so I wrote the article from a neutral position!
I write these articles to help those who need help to be able to better understand how real process safety works. But one of the referenced codes in those 2016 and 2019 articles is one that I have not written about and it has recently raised its head in another project… ASME PCC-2.
What does this little ASME code bring to the table and when should I be utilizing it?
Well, as I said in 2016 and 2019 after we break the integrity boundary on a circuit of piping and we rebuild the piping after our maintenance work, we are supposed to perform a pressure and leak test very much like we did when the “new” pipe was installed using one of the ASME B31 series of piping codes. ASME PCC-2, as referenced in ASME B31 and API 570, is the code to use on piping that has been IN SERVICE and we need to test it. So here is how we would use ASME PCC-2 (first published in 2004)…
So first off, the title of ASME PCC-2 says a lot: “Repair of Pressure Equipment and Piping”
When the title of the code has the word repair, it is pretty clear this code covers equipment that has been IN SERVICE and needs to be tested after its use versus testing a NEW INSTALL.
The code comes in five (5) parts and I am ONLY writing about Part 5 – Examination and Testing
Part 1 – Scope, Organization, and Intent
Part 2 – Welded Repairs
Part 3 – Mechanical Repairs
Part 4 – Nonmetallic and Bonded Repairs
Part 5 – Examination and Testing
The forward of this code explains its intent… (emphasis by me)
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ASME formed an Ad Hoc Task Group on Post Construction in 1993 in response to an increased need for recognized and generally accepted engineering standards for the inspection and maintenance of pressure equipment AFTER IT HAS BEEN PLACED IN SERVICE. At the recommendation of this Task Group, the Board on Pressure Technology Codes and Standards (BPTCS) formed the Post Construction Committee (PCC) in 1995. The scope of this committee was to develop and maintain standards addressing common issues and technologies related to POST-CONSTRUCTION ACTIVITIES and to work with other consensus committees in the development of separate, product-specific codes and standards addressing issues encountered after initial construction for equipment and piping covered by Pressure Technology Codes and Standards. The BPTCS covers non-nuclear boilers, pressure vessels (including heat exchangers), piping and piping components, pipelines, and storage tanks. |
A statement in the forward I found interesting…
| None of these documents are Codes. They provide recognized and generally accepted good practices that may be used in CONJUNCTION WITH POST-CONSTRUCTION CODES, such as API 510, API 570, and NB-23, and with jurisdictional requirements. |
So again, ASME is making it crystal clear that this RAGAGEP is to be used in CONJUNCTION WITH POST-CONSTRUCTION CODES, such as API 510, API 570, AND NB-23.
Now that we have the introductions done, let’s dive into the use of this RAGAGEP, specifically Part 5 – Examination and Testing.
Something important to point out is that all of Section 5.1 was re-written in its entirety in 2008 and this was big as this section sets the scope of use.
This Article shall be used for field pressure or tightness testing of existing equipment and piping using either of the two-fluid mediums, liquid or gas. But it specifically states this RAGAGEP shall not be used for vacuum testing.
Article 5 addresses pneumatic testing and states:
“Pneumatic testing is potentially hazardous, much more than hydrostatic testing due to the higher levels of potential energy in the pressurized system; therefore, all reasonable alternatives shall be considered before this option is selected.”
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3.2 Reasons for Pressure and Tightness Testing (a) The primary purpose of performing a pressure test is to verify the integrity of a pressure system. This is especially true when welded repairs or alterations (b) Pressure or tightness tests can be used to check for pressure system leakage, especially in flanged joints. Tightness tests may be performed in conjunction with the pressure test. (c) Hydrostatic pressure testing can provide some mechanical stress relieving. …. (d) Tightness testing may be considered when structural integrity does not need to be verified but when leak tightness must be verified prior to start-up. (e) In-service leak testing can be considered when structural integrity does not need to be verified and the consequences of a leak during start-up are acceptable, or when permitted by the applicable code of construction or post-construction code. |
Next posting we will cover how to determine if we pneumatically or hydrostatically test our IN-SERVICE piping.