I think these notes which we prepared should keep every welding and and piping engineers and inspectors. This article is about Welding QC and Engineer Notes of Aramco and international codes and standards. These questioned also can be CBT Examination of Aramco.
Welding QC and Engineer Notes
Following points to keep save with you regardless how many years of experience you have.
- The standard for process (or) plant piping systems is ASME B31.3.
- The standard for power piping systems is ASME B31.1.
- The standard for liquid petroleum transportation and distribution piping systems is ASME B31.4.
- The standard for gas transmission and distribution piping systems is ASME B31.8.
- The code for welding of pipelines and related facilities is API 1104.
- The standard for welding rods, electrodes, and filler metals is ASME Sec-II Part C.
- The standard for non-destructive examination is ASME Sec-V.
- The standard for welding and brazing qualifications is ASME Sec-IX.
- In field/shop fabrication, the fusion welding process is commonly used.
- The specification/classification for carbon steel filler wire is AWS 5.18/ER70-Sx.
- The specification/classification for carbon steel electrode is AWS 5.1/E-XXXX.
- E-6010 type electrode is commonly used at the root pass for deep penetration.
- ASME stands for the American Society of Mechanical Engineers.
- The type of electrode used in GTAW (Gas Tungsten Arc Welding) process is a non-consumable tungsten electrode.
- When handling electrodes:
- Different grades of electrodes should be stored separately.
- They should be kept clean, dry, and properly stored according to the manufacturer’s recommendations.
- Low hydrogen electrodes should be baked and stored in heated containers before use.
- Electrodes used should be free from rust, oil, grease, earth, and other foreign matter. 15A. Electrodes can typically be dried only once.
- Electrodes are baked to remove moisture content and ensure better weld quality.
- The standard for structural steel fabrication is AWS D1.1.
- The standard for welding symbols is AWS A2.4.
- The hydro test pressure is typically 1.5 times the design pressure.
- The drying temperature for stainless steel electrodes ranges from 120 to 250 degrees Celsius.
- The drying procedure for low hydrogen electrodes involves baking them at temperatures between 260 and 430 degrees Celsius for two hours.
- Visual inspection can detect defects such as porosity, undercut, surface cracks (HIC), and side wall fusion on the fusion boundary.
- The procedure for fit-up inspection includes checking base metal classification, cleaning, alignment, root gap, root face, bevel angle, and mismatch or overlap.
- The maximum allowed internal overlap or mismatch for piping is 1.5mm.
- The allowed root face may vary depending on the Welding Procedure Specification (WPS), but typically it ranges from 0.8mm to 1.6mm.
- The F-number stands for filler metal grouping number.
- The P-number stands for base metal grouping number.
- The A-number refers to the electrode’s chemical analysis number.
- The maximum allowed bead width is typically three times the diameter of the electrode.
- A minimum preheat area of 75mm from both ends of the joint is typically required.
- NDT (Non-Destructive Testing) is covered in ASME Sec-V.
- Essential variables for SMAW process include base metal thickness, P-number, diameter of pipe, preheat, and post-weld heat treatment. For filler metals, F-number, A-number, and diameter of filler metal are essential variables.
- Essential variables for GTAW process are similar to SMAW, including base metal thickness, P-number, diameter of pipe, preheat, and post-weld heat treatment. Filler metal variables such as F-number, A-number, and diameter are also essential.
- If a welder passes a test with a 2″ diameter, their qualified range is 1″ diameter and above.
- If a welder tests with a 14mm thickness, their qualified thickness range is unlimited.
- The maximum carbon percentage in low carbon steel is 0.30%.
- The interpass temperature for carbon steel materials should not exceed 315 degrees Celsius.
- SAES stands for Saudi Aramco Engineering Standards, SAEP stands for Saudi Aramco Engineering Procedures, and SAMSS stands for Saudi Aramco Materials System Specifications.
- The allowed depth of undercut in piping is 0.8mm.
- The pressure relief device can be set to the test pressure plus 10%, provided that the additional 10% does not exceed 50Psi.
- A minimum gap of 1.5mm is allowed in socket weld before welding.
- The minimum fillet weld size in socket weld is 3mm.
- The high-frequency unit in GTAW process is used to avoid tungsten inclusion and arc strike.
- The suffix letter ‘G’ in electrode AWS specification indicates that the electrode is used for low-temperature service (LTS) materials with a chemical content of less than 1% for elements like Mn, V, and Mo.
- WPS stands for Welding Procedure Specification, which is a collection of data that ensures the production of sound welds. It includes essential, non-essential, and supplementary variables.
- Cr (Chromium) and Mo (Molybdenum) materials fall under P4 and P5 respectively in the P-number classification.
- Essential variables are those that, when adjusted or changed in the welding process, have an impact on the mechanical properties of the weld.
- Types of supports include anchor supports, T-supports, shoe supports, guide supports, pedestal supports, cantilever supports, hanging supports, dummy supports, trunnion supports, and wear pad supports.
- Types of flanges include weld neck flange, slip-on flange, blind flange, threaded flange, socket flange, and lap joint flange.
- Classes of flanges are categorized by pressure ratings and include 150, 300, 400, 600, 900, 1500, and 2500.
- Types of pipes include welded type and seamless pipes and tubes. Schedules refer to pipe thicknesses, such as SCH-10, SCH-20, SCH-30, SCH-40, SCH-60, SCH-80, XS, SCH-100, SCH-120, SCH-140, SCH-160, and XXS.
- Types of gaskets include spiral wound gasket, composite gasket, corrugated gasket, die-cut gasket, and solid metal gasket.
- Materials familiar with include LTS (Low Temperature Service), CS (Carbon Steel), SS (Stainless Steel), Duplex, Copper Nickel, and Low Alloy Steel.
- Familiar with fluid services such as normal fluids, D (Dangerous) fluids, and M (Moderate) fluids.
- A string bead refers to a straight motion of welding without side-to-side motion, such as in SAW (Submerged Arc Welding).
- A weave bead refers to a side-to-side motion while welding.
- WPS (Welding Procedure Specification) is approved based on the weld meeting the minimum requirements of mechanical, chemical, and physical properties.
- Parameters required to prepare a WPS include pipe diameter, thickness, welding position, current, voltage, electrode, and base metal.
- SAES-W-010 is the standard used in Aramco for welding requirements of pressure vessels.
- SAES-W-011 is the standard used in Aramco for on-plot piping.
- SAES-W-012 is the standard used in Aramco for welding requirements of pipelines.
- On-plot piping refers to inside plant piping.
- Off-plot piping refers to outside plant piping.
- Specifications used for pipe manufacturers include API 5L and ASTM.
- PWHT (Post Weld Heat Treatment) is performed to release stresses in the welded material.
- Acceptable hardness methods in procedure qualification include Vickers, Brinell, and Rockwell hardness methods.
- Piping materials on the shop floor can be visually identified through color coding and stamping.
- Radiographs of specific pipe welds can be ensured by identifying the welds on films and sometimes drawings.
- Information contained in a radiograph of a pipe weld includes the penetrameter, joint number, and welder ID.
- Precautions when welding alloy materials such as 1.25Cr and 5Cr include preheating, controlling interpass temperature, and performing PWHT (Post Weld Heat Treatment) as per requirements.
Read Also:
Piping QC Course of Aramco & SABIC Part-1
Piping QC Course of Aramco & SABIC Part-2