Positive Material Identification Procedure

This content provides you with a sample positive material identification procedure. This PMI test procedure must be modified based your project specification. This procedure has been prepared for industrial plant construction project and contains both shop and site inspections. 

1. Introduction

The XXX company has been contracted by the xxx to conduct the EPC for XXX Project. This Project includes offshore facilities, platform and undersea pipelines, and onshore facilities for the processing of the reservoir fluid.

2. Project Overview


3. General

3.1 Scope

This procedure prescribes the requirements for the positive material identification (PMI) for vessels and piping to verify that alloy materials are of acceptable chemical composition independent of any certificate and marking that may exist, and to assure that correct alloy materials are used at the places where intended. "AV" low stress stamp will be applied for the marking.

3.2 Definition of Contracting Parties

Company: XXX

Contractor: XXX

Vendor: Company who will supply and/or manufacture equipment and/or materials under Purchase Order issued by Contractor

Inspector: Inspector dispatched by Contractor/Company or inspector of third party inspection agency designated by Contractor

EPCC: Engineering, Procurement, Construction & Commissioning

SBM: Single Buoy Mooring

PMI: Positive Material Identification

3.3 Referenced Documents

This Procedure shall be read in conjunction with the following Documents:

XXX Project Quality Plan

XXX General Requirements for Welded Fabrication

XXX Specification, Design and Fabrication of Pressure Vessels

XXX Steel Piping Fabrication

XXX General Work Procedure for Welding

XXX Non Destructive Testing Procedure

XXX Site Material Approval Procedure

ASME B31.3 Process Piping

ASME Section II Part C Materials

DINEN 10204 Metallic products - Types of inspection documents

ASTM E 1476 Standard Guide for Metals Identification, Grade Verification, and Sorting

ASTM E 572 Standard Test Method for Analysis of Stainless and Alloy Steels by X-ray Fluorescence Spectrometr

ASTM E 322 Standard Test Method for X-Ray Emission Spectrometric Analysis of Low- Alloy Steels and Cast Irons

4. Extent of PMI

4.1 Materials

4.1.1 This procedure shall be applied to the following low alloy / Stainless Steel / high alloy materials, i.e.: 

1) Low alloy steel containing more than 1 Cr - 0.5 Mo and/or 3.5 Ni 

2) Type 316/316L stainless steel

3) Type 321/347 stainless steel

4) 11-13% Cr (Type 410/410S/40S)

5) Nickel Alloy such as INCONEL&HASTELLOY

6) Cooper Nickel Alloy

7) Aluminum -Bronze

8) Titanium

9) Other materials as mentioned in table 1.

Examination of the base materials to be carried out. Elements to be determined during PMI shall be as per Table.1.

4.2 Positive Material Identification Extent of Examination

4.2.1 This procedure shall be applied to the pressure containing parts of following items including welded joints and components (plates, forgings, nozzle(pipe), flanges, internal lining, tubes etc.) to the pressure containing parts of Pressure Vessels and Piping mentioned below para.1 and 2, respectively:

Also it shall be applied to the similar part in the package units.

1) Equipment

a) Pressure vessels, such as reactors, towers, drums, heat exchangers, air cooled heat exchangers

b) Fired heaters (only heater coils)

2) Piping

a) Pipes

b) Fittings

c) Flanges

d) Valves

The welded joints and components shall be tested after fabrication. For PMI test of tagged items, mill certificates shall cover all bulk items and components before fabrication.

All parts that are tested in the fabricated form should be 100% verified.

5. Sampling Procedure

5.1 Positive Material Identification (PMI) of Equipment at Vendor's Shop

The vendor shall perform PMI examination of the finish weld on the one point of each joint inside and outside for all weld joints. When access is not possible to the inside weld and/or weld size is small, examination of the outside of a weld only shall be acceptable.

5.2 PMI of Piping Bulk Materials at Vendor's Shop

5.2.1 The vendor shall perform PMI examination of all samples chosen at random from an inspection batch. Unless otherwise specified, inspection will be carried out at random for at least 1 (one) per each heat, minimum 3 points on each length of examined pipe to be carried out.

5.2.2 If any item from sample is found to be unacceptable, all remainder of that batch and two subsequent inspection batches shall be performed 20% PMI examination.

5.3 Positive Material Identification of Welded Joints at Site

5.3.1 After installation on the final location at site, the color code marked on the piping systems shall be checked and recorded by the Construction Contractor.

5.3.2 Finished groove weld in alloy piping system shall be examined on the one point of each joint for 5% groove weld joint.

5.3.3 Finished groove weld of alloy equipment assembled at Site shall be examined on the 5% random basis for all welded joints.

5.4 PMI of Components at Site

PMI of equipment is not required at site since PMI examination of these items shall be done at Vendor's shop, but for piping components such as pipes, fittings & flanges, material traceability shall be performed in accordance with the document No. XXX Procedure for Heat Number Traceability for Piping Material.

If material traceability has not been done properly, PMI is required for such part of piping compounded at site.

Also for PMI of deposited weld metal at site, refer to Method Statement for Positive Material Identification - XXX.

6. Positive Material Identification Examination Method

6.1 Instruments used to perform PMI shall conform to one of following:

6.1.1 Portable X-ray emission or fluorescence spectrometers with direct reading of alloy grade or composition in the applicable range, such as "Texas Nuclear 9266" or META scope or equivalent.

6.1.2 Molybdenum in type 316 and 316L stainless steel may be checked with reagent.

6.2 The traces of PMI examination shall be taken off not to adversely affect the end use of items.

6.3 Reagent shall be washed off with water not to adversely affect to the end use of items and corrosion.

6.4 The construction contractor shall submit the PMI examination procedures which include following:

6.4.1 Equipment to be used 

6.4.2 Washing of reagent

6.4.3 Control sheet of examination

6.4.4 Report form

7. Positive Matreial Identification Acceptance Criteria

Alloy elements specified in chemical composition of materials shall be detected at the PMI examination. Acceptance criteria range for all the project material to be tabulated as per related standard. Acceptable range shall include the tolerance of the measuring equipment, which is provided with manual by equipment's maker

8. Color Code

8.1 For piping bulk materials, all items in an inspection batch shall be marked color code by the vendor. The color-coding for pipes shall be marked whole length of pipes after acceptance has been made.

9. Records

9.1 The vendor or the Construction contractor shall record the results of examination on a report form which indicates following as a minimum:

9.1.1 Item number of equipment, name of piping bulk material or welding joint number of piping systems

9.1.2 Material specification number and grade

9.1.3 Mill certification number

9.1.4 Inspection batch size

9.1.5 Number of items examined

9.1.6 Chemical composition detected

9.1.7 Measuring equipment used for examination with type, model, etc.

9.1.8 Signature and date of the representative of the supplier or the Construction Contractor

9.1.9 Calibration certificate of the positive material identification equipment

9.1.10 PMI report shall be as per DIN 50049 or BS/EN 10204 type 3.1C or 3.2. (In the meantime, PMI shall be witnessed by Company according to inspection and test plan enclosed in the Material Requisition).

9.1.11 PMI performed by the Vendor shall be presented to the Company/Contractor's inspector for his review and will be compiled into Manufacturer's Data Records at the completion of fabrication or manufacturing.

Table.1 Elements to be determined during PMI

Materials (1)Elements to be determined
1% Cr, 0.5% MoCr, Mo
1.25% Cr, 0.5% MoCr, Mo
2.25% Cr, 1.0% MoCr, Mo
9% Cr, 1% MoCr, Mo
11-13% Cr (Type 410/410S/40S)Cr
304 (L)Cr, Ni, Mo, Nb(Cb), Ti
310Cr, Ni, Mo, Nb(Cb), Ti
309 (L)Cr, Ni, Mo, Nb(Cb), Ti
309 NbCr, Ni, Mo, Nb(Cb), Ti
316 (L)Cr, Ni, Mo, Nb(Cb), Ti
321Cr, Ni, Ti, Nb(Cb)
347Cr, Ni, Nb(Cb), Ti
Alloy 600Cr, Ni, Mo, Nb(Cb) + Ta
Alloy 625Cr, Ni
Alloy 800/800HCr, Ni, Al, Ti, Cu
AWS A5.11 ENiCrFe-2Cr, Ni, Nb(Cb) + Ta
AWS A5.11 ENiCrFe-3Cr, Ni, Nb(Cb) + Ta
AWS A5.14 ERNiCr-3Cr, Ni, Nb(Cb) + Ta
2205 DuplexCr, Ni, Mo
Admiralty BrassCu, Sn, As
Aluminium BrassCu, Al, Zn
Cupro-nickel (70-30)Cu, NI
Cupro-nickel (90-10)Cu, Ni
Monel 400Cu, Ni

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