UNS S The individual alloys tend to have broader environmental limits than those set for the group. Suitable labeling or documentation is also acceptable. A summary of the content described below is presented in a flowchart diagram in Appendix B, see Appendix B. For design using plastic criteria strain—based and limit states use of this standard may not be appropriate. Note: All items in this section are repeated in both Part2 and Part3 of the standard. Clause 6. Clause 8. Testing may be conducted under service conditions similar to the limits applied to pre-qualified materials or under service conditions outside these limits.
The parameters affecting the behavior of carbon and low alloy steels in H2S environments are explicitly listed metallurgy, H2S partial pressure, pH, chloride content, etc. The user must evaluate the severity of the service environment based on a combination of H2S partial pressure and in service pH. Any other test method requires explicit user approval.
Clause 7. Hardness testing shall be specified as part of the qualification for fabrication methods such as burning and cutting if any HAZ remains in the final product. To address this prospect, additional testing and specific acceptance criteria may be required. For example, when selecting any austenitic stainless steel for a general application, the service environment limits and material requirements are listed in Table A.
However, if the austenitic stainless steel is UNS S, then the specific limits listed for this particular austenitic grade must be used. The hardness limits for material types or individual alloys are listed in Annex A. Note: The use of the HRC method requires specific user approval. This includes qualification testing for fabrication methods such as burning and cutting if any HAZ remains in the final product.
Some environmental restrictions are placed on certain alloys based on the PREN number 5. This effort introduced fundamental changes to the MR, incorporating industrial practices and testing methodologies previously not addressed by MR As stated above, the new standard addresses issues which were not considered in the previous versions of NACE MR and which may have significant implications for the users of the document. All maintenance issues such as interpretation, amendments or total revisions must be submitted directly to the designate or focal point appointed by the MP.
These ballots are presented to the OSC membership for voting. The most substantial change in the document was to stainless steels. Figure 4.
The increased emphasis on end user responsibility was established to ensure the correct material was being selected for the intended environment. Figure 1 of Part 2: Clause 7. This differs from previous editions where only the partial pressure of the H2S was considered. Hardness requirements for welds Part 2: Clause 7. Other test methods require the agreement of the equipment user. This differs from previous editions where HRC was the primary basis of acceptance.
Previous standard versions only considered SSC as the governing cracking mechanism. For example, austenitic stainless steels e. In previous editions, only sulfide stress cracking SSC was considered; there were no temperature restrictions. In previous editions of MR, several legacy materials had no environmental restrictions, implying they were suitable for any sour service environment.
For example, wrought precipitation hardening nickel alloy UNS N had no environmental restrictions in previous editions of MR; in the current standard this alloy has H2S partial pressure limitations based on the maximum operating temperature. The environmental limits listed in Tables A. For example, austenitic steels such as AISI are limited to a maximum of kPa partial pressure of H2S at a maximum temperature of 60oC for any combination of chloride concentration and in situ pH in the production fluid.
These categories or materials groups austenitic steel, martensitic steels, etc are further split into material types similar compositional limits and individual alloys.
For example, Annex A, Table A. Developed for members by members, the Professional Standards offer career centers the opportunity to assess, develop, and enhance their operations by assessing operations along 13 dimensions. Revised in by a task force of NACE member career services professionals, the Professional Standards provide the profession with a foundation on which to ensure excellence.
Career Center. Work at AMPP. Privacy Policy Terms of Use. This website uses cookies to ensure you get the best experience on our website. Learn more. Skip to main content Press Enter. Skip auxiliary navigation Press Enter.
Many applicators perform their own inspection or hire an independent inspection agency. The intent of this NACE standard recommended practice is to provide appropriate inspection requirements to verify compliance to the specification. It is not intended to address the selection of a coating or to specify surface preparation and application requirements. For further information about selecting and specifying surface preparation methods for concrete before application of linings, users of this standard should refer to ICRI Technical Guideline 3 For further information on the design, installation, and inspection of linings users of this 4 5 standard should refer to NACE No.
For the purpose of this standard, the terms linings and coatings are synonymous. Shall and must are used to state mandatory requirements. The term should is used to state something considered good and is recommended but is not mandatory.
The term may is used to state something considered optional.
0コメント