The purpose of RP 578 is to provide guidelines for a material and QA system to verify the composition and alloy components within the piping system are consistent with the specified construction materials to minimize the potential for release of toxic or hazardous liquids or vapors.
RP 578 also provides guidelines for material control and material verification programs on ferrous and non-ferrous alloys of new and existing systems specifically covered by B 31.3 (New Process Piping) and API 570 (In Service inspection) during:
Construction Installation Maintenance Inspection
RP 578 applies to metallic alloy materials purchased for use:
Directly by the owner.
Indirectly through vendors, fabricators, or contractors.
Includes the supply, fabrication and erection of these materials.
1.2 Alloy Substitutions in Carbon Steel Systems
When determining if carbon steel systems require material verification, the owner/user should consider what effect the process stream could have on a substituted alloy material.
Substitutions of hardenable alloy materials in carbon steel systems have resulted in failure and loss of containment.
Examples:
Wet H2S
Hydrofluoric acid
And sulfuric acid
1.3 Roles and Responsibilities
Consideration should be given to the roles and responsibilities that each group involved in the material verification program has. Groups within the operating plant or shops of contractors, vendors or fabricators should have roles and responsibilities clearly defined and documented.
Groups can include:
Purchasing Engineering Warehousing/receiving Operations Reliability Maintenance
2.0 References
Refer to the listed referenced publications in Section 2.
3.0 Definitions
Refer to section 3 for definitions related to Material Verification Programs.
4.0 Extent of Verification
4.1 General
The owner/user should establish a written material verification program indicating the extent and type of PMI testing to be conducted during construction of:
New piping systems
Retroactively on existing piping systems
Maintenance and repairA.
The owner/user should consider performing a high percentage of examinations for higher-risk systems.B.
Lower risk-systems could have random sampling performed.C.
Material substitution problems tend to be random and small sampling may not locate all substitutions.4.2 New Construction Q/A Material
Verification Program
Covers shop and field fabrication of alloy pipe.
Prior to being put into service.
Is restricted to pressure containing boundaries.4.2.1 Responsibilities
The owner/user or designee is responsible for:
A.
Determining the extent of examination needed.B.
Verify implementation and conduct of the program is performed in accordance with RP 578.C.
Verify that alloy materials placed into service are as specified.D.
Documentation of the material program is in accordance with this recommended practice.4.2.2 Material Verification Test
Procedure Review
When PMI testing is performed by the material supplier or third-party agency; the owner/user should review and approve the adequacy of the material verification program and testing procedure of the fabricator or material supplier prior to testing.
4.2.3 Scheduling of Material
Verification Testing
PMI testing should be conducted at a time that ensures that proper alloy materials have been used in the fabrication of an identifiable assembly.
4.2.4 Mill Test Report
Although this is an important part of a material QA program, MTRs should not be considered a substitute for PMI testing.
4.2.5 Components Covered in a Material Verification Program
Examples:
a. pipe lengths b. pipe fittings c. flanges d. special forgingse. processes valves and RVs
f. instruments
h. weld overlays or cladding
i. bolting
4.2.6 PMI Testing of Welding Consumables
Should PMI one electrode or wire sample form each lot or package of alloy weld rods.
Should compare remainder of the lot to sample to verify markings are correct.Because of alloying elements in flux, PMI testing of weld metal is an acceptable alternative provided it is conducted immediately after welding or during the welding process.
4.2.6.1 Longitudinal Pipe and Fitting Welds
Should receive random PMI of the base metal and weld metal.
4.2.6.2 Autogenous welds
If required, it only necessary to test the base metals.
4.2.7 PMI testing of Components Supplied
by a Distributor
A higher degree of PMI testing should be performed due to the potential for material
4.3 Material Verification Program For
Existing Piping Systems
Section covers alloy piping in service where material verification programs were not in accordance with 4.2
Material verification is limited to pressure containing components and attachments welds.4.3.1 Responsibilities
The owner/user is responsible for:
Determining if a retroactive material verification program is required for existing piping systems.
Prioritizing the piping systems to receive retroactive PMI testing.
Determining the extent of PMI testing required.4.3.2 Prioritizing piping systems for retroactive
PMI Testing
When determining if retroactive PMI testing is necessary, the owner/user should consider the following:
a.
likelihood of material mix upb.
consequence of a failurec.
reason for alloy specificationd.
related historical data- non-conformance report Owner/user should establish a methodology for prioritizing PMI testing. Methodology may be based on a qualitative or quantitative risk analysis.4.3.2.1 Carbon Steel Substitutions in Low Alloy
Steel Systems.
Historically, low alloy steel has the greatest number of material non-conformances with serious consequences.
4.3.2.2 Other Factors to Consider When
Prioritizing Piping Systems
Site specific or experienced-based factors should be considered when prioritizing piping systems.
Factor to consider:
4.3.3 Component Prioritization Factors
Piping components may have a higher likelihood or inadvertent substitutions of a non-specific material.
Examples are:
a.
warm up and bypass lines on pumps or check valves.b.
small diameter piping systems.c.
valves and other removable devicesd.
thermowellse.
boltingf.
piping as apart of a packaged system4.3.4 Factors to Consider when Determining
the Extent of PMI testing
a.
Historical inspection material verification records.b.
Number of plant modifications.c.
Material control during original fabrication.d.
Material verification program during construction and fabrication.4.4 Material Verification Program as Element
of Maintenance Systems
Concepts in 4.2 and API 570 should be reviewed and applied as applicable.
4.4.1 Responsibilities
It is the owner/user’s responsibility to verify programs are designed and implemented to support the MI of alloy piping.
A material verification procedure should also be written to address the repair of piping systems during maintenance outages.
4.4.2 Control of Incoming Materials and
Warehousing
PMI testing can be as part of receiving function or performed at the supplier’s location (as a condition of release for shipment).
Material verification in the warehouse should be regarded as a QA practice to minimize potential discrepancies during subsequent PMI testing but should not be regarded as an alternative to PMI testing of fabricated systems when
4.4.3 Maintenance Repairs of Piping
Systems
Important to consider PMI testing of the repair materials.5.1 Material Verification Program Test Method
Objectives
Methods of RP 578 are intended to ID alloy materials and not intended to establish the exact conformance of material to a particular spec.
Depending on the test method used, PMI testing may identify the nominal composition of the material.
5.2 PMI Test Methods
Portable x- ray fluorescence
portable optical emission spectroscopy laboratory chemical analysis
There are also alloy-sorting techniques may be appropriate. These techniques can include magnetic testing to differentiate between ferritic and austenitic.
5.2.1
Portable X-ray Fluorescence5.2.2
Portable Optical Emission Spectrometry5.2.3
Chemical Laboratory Chemical Analysis5.2.4
Other Qualitative Tests5.2.4.1 Chemical Spot Testing
5.2.4.2 Resistivity Testing
5.3 Equipment Calibration
Calibrate or verify the test equipment as specified by the equipment manufacturer
PMI test procedure should provide frequency interval.
If the manufacturer does not provide calibration procedures, the owner/user should establish them.
Procedures should include calibration verification using certified standards.
5.4 Equipment Precision
Should be consistent with established test objectives (see 5.1).
When composition is required, the owner/user should establish the acceptable precision and repeatability.
5.6 Safety Issues
Should consider electrical arching and hot spots.
Consider appropriate electrical and hot work permits.
Take safety precautions when handling chemicals used in chemical spot testing.
6.0 Evaluation of PMI Test Results
6.1 Material Acceptance Methods
Confirmation of materials by the use of relevant material specifications (e.g. ASME Sec II or ASTM).
Materials can be classified through qualitative sorting techniques.
When PMI testing indicates alloying elements are outside the material specification ranges, the owner/ user can choose to allow the use of the materials provide a knowledgeable person confirms that the material will perform satisfactorily in the service.
If portable or qualitative PMI testing leads to a potential rejection, a more accurate analysis may be used to determine component acceptance.
6.2 Dissimilar Metal Welds And Weld Overlays
When testing dissimilar welds, consider the effects of dilution, which occurs during, weld deposition.
6.3 Follow-Up PMI Testing After Discovery Of A
Nonconformity
If a representative sample is rejected, all of that lot should be considered suspect and more extensive inspection should be conducted of the remaining lot.
7 Marking and Record-keeping
7.1 Materials Identification Process
Acceptable examples:
a.
Color coding by alloyb.
Stamp markingc.
Documentation of PMI results and test locations7.1.1 Color Coding/Marker
If visual identification (color coding or marking) is required by the material verification program, records of the alloy material/ color-code combinations should be maintained by the owner/user.
Color-coding is not a substitute for permanent manufacturers markings required by ASTM or other material specs.
7.1.2 Marking or Components
Documentation process should specify one of the following:
If the marking system is to remain for the expected life of the component.
the marking system is only to be temporary.
7.2 Material Certifications.
Should not be considered a substitute for PMI testing.
7.3 Shop And Field PMI Test Documentation
7.4 New And Existing Piping System
Documentation
Records of results for PMI testing should be kept as long as the piping system exists in its original location.
Should consider PMI testing prior to placing relocated components into service for piping that has no records of material verification
7.5 PMI Test Records
Test records should contain:
a.
Reference to the PMI test procedure(s) used.b.
Date of testing.c.
Test instruments identification number or serial number (where appropriate)d.
Name of each person and company performing the test.e.
Results of the test.f.
Basis and action for resolving and documenting PMI test including those that have been left in service.g.
Documentation of the criteria used for prioritization of piping systems and the extent of PMI testing performed.7.6 PMI Test Procedures
Should include:
Techniques used
Equipment calibration
Qualification requirements for PMI test performed
The testing methodology
7.7 Traceability To Field Components
The information in 7.5 should be reported in such a manner that they are traceable to the point of installation.
