One MTC or MTR is without a doubt one of the most important documents in every facility in oil and gas industry assuring the quality of the materials being produced. Every scale of the raw material whether it’s pipes, fittings, flanges or plates requires the manufacturer to have a proper MTC for the intended product. This forms an important paper trail – on the basis of standards, required and supplied construction material’s chemistry and mechanics, and the sources of such product.
The role of the inspecting engineer is also to check that the MTC conforms to standards, specifications of the contract as well as requirements given in the purchasing order. This check also covers factors such as material-type, size and weight, the chemical make-up or composition, physical properties, the non-destructive examination (NDE) tests done and also the heat treatment employed. Below is a detailed guide on how you can effectively review MTCs.
Step 1: Establishing the Material Certificate Type
The first stage is to define the kind of material inspection certificate that was issued and of course understood by the parties, which is mostly based on standards such as BS EN 10204. Generally Accepted Materials Standards Types 2.1, 2.2, 3.1 and 3.2 are commonly used, with each being a distinct degree of inspection and documentation. To illustrate, a 3.1 certificate bears assurance that the material was inspected by the internal inspectors of the fabricator and a 3.2 certificate entails 3rd party verification for materials intended for critical applications. It is a must to check that the certificate type satisfies the certification requisites aroused in the purchase order.
Step 2: Considering the Administrative Information
The administrative info of the parties MTC includes , name of the manufacturer, name of customer, order number, work order number etc. This information in applicable MTC provides basis for linking it with purchase order and therefore reducing chances of materials being inspected which are not relevant to the project or work being undertaken.
Step 3: Checking the Manufacturing Procedure
It is usually written in MTC what manufacturing process was employed for the material. For instance, seamless pipes can be made using hot rolling, cold rolling and forging. The method adopted should satisfy the requirements regarding the material grade included in the standards and in the order proposed.
Step 4: Reconnaissance of the Product Type and the Surface Condition
In accordance with the MTCS the product has been specified as one of those, seamless, ERW, spiral wound or LSAW welded pipes. It also states the surface condition, namely rust preventive varnish, whether it is galvanised or is bare. These particulars should correspond with the purchase order and the desired utilization of the material.
Step 5: Examination Warranting the Adherence to Established Standards and Specifications
The certificate should provide a list of the standards which the material meets such as API, ASME, ASTM and NACE standards, for example. Materials which are compliant with NACE MR0175 and MR0103 are example of materials which can withstand corrosive environments. Compliance verification is necessary to ensure that the required material of the appropriate quality and performance has been obtained.
Step 6: Verification of the dimensions and The End Types
The MTC contains various important information including dimensional information such as the length, diameter and thickness of the pipe as well as the basic features such as plain ends, beveled ends or threaded ends. The details captured must also form part of the project requirements. Small bore pipes are in most cases described as having plain ends while thick-walled pipes are described as having beveled ends for welding purposes.
Step 7: Testing Mechanical Components and Results
Yield strength, ultimate tensile strength (UTS), and elongation are some of the many characteristics of a material which determine the performance of a mechanical component made out of that material. Types of material properties such as these, as well as the results achieved during the testing phase are to be stated in the MTC in terms of minimum and maximum acceptable values. It is paramount that these resultant test outcomes fall within a defined zone in order for the material in question to be accepted.
Step 8: Explanation of Chemical Composition
The section in the MTC that covers chemical analysis shows the alloying elements and the percentages of them contained in the material. This information makes it possible to verify whether the composition of the metal in question meets the stipulated requirements. For instance, the carbon content and other alloying ingredients such as manganese, phosphorus or sulfur need to be controlled.
Step 9: Conducting Hardness Test and Other Specific Tests
Hardness test data which is expressed as Brinell Hardness Numbers (BHN) are incorporated in the MTC so as to confirm that the surface properties of the material are within the specifications. For materials that are exposed to destructive environments, further tests such as hydrogen-induced cracking (HIC) or sulfide stress cracking (SSC) can additionally be carried out.
Step 10: Assessing the Results after the Bend and Hydrostatic Tests
Bend tests measure the ductility and crack resistance of a material. During the test itself, it is visually checked whether any cracks develop at the qualification stage. Hydrostatic testing evaluates the pressure rating in units of, for example, PSI. These tests certify the suitability of the material for its intended purpose or use.
Step 11: Checking Heat Treatment Specifics
MTC also provides the heat treatment particulars like normalization or quenching as needed for the material to meet the expected mechanical properties. The specific temperature, the time to hold the sample at that temperature, and the cooling methods are to be as specified in the applicable standards.
Step 12: Making Use of Non-Destructive Testing (NDT) Results
The MPT and UT NDT results also assure the structural integrity of the material. These tests locate surface and sub surface flaws within and beneath the metal surface to rule out cracking or pitting of the area under consideration.
Step 13: Examination of MTC regarding Marking and Traceability
Marking features which are of the importance are such as the manufacturer’s name, material grade, size, heat number, standard, and other or applicable standards, all these should appear in the MTC. These markings provide traceability in the lifecycle of the material and assist in locating the material easily during its life cycle.
Conclusion
The evaluation of a Material Test Certificate is rather delicate and requires considerable understanding of the pertinent standards and the project’s requirements. Following the steps outlined above assists the inspection engineers in ensuring the quality, traceability and compliance of the material. This practice reduces risks, promotes safety and preserves the integrity of the materials used in vital functions.
