Workshop for Pressure design of Fittings (16th Session of ASME B31.3)

🎓 Do you know how to specify the class/rating of a forged 90 degrees elbow under specific conditions? Imagine a scenario where you need to determine the class for an elbow with the following parameters: NPS=1 ½, Material=ASTM A105, and Corrosion Allowance=1 mm. Additionally, are you acquainted with PMS (Piping Material Specification)? In this episode of ASME B31.3 with Ali, we delve into the intricacies of specifying the class of fittings based on project PMS and enhancing your understanding of materials.
👋 Hello and welcome to the 16th session of our ASME B31.3 Course! I'm Ali, and I'm glad to have you here. Today, we delve into specifying the class and thickness of fittings based on ASME B31.3 and related standards.
🛠️ *Materials Overview:*
Before we dive in, let's touch on materials. Carbon steels, with up to 2% carbon content, are crucial in piping components. ASTM standards like A105 and A234 govern their manufacturing, with variations like low temperature carbon steels, low alloy steels, high alloy steels, and non-ferrous materials also playing key roles.
📏 *Forged Fittings Class Specification:*
When specifying the class of a forged fitting, such as a 90 degrees elbow, we consider factors like NPS (Nominal Pipe Size), material, and corrosion allowance. Notably, design pressure and temperature are determined by the pipe's wall thickness, as per ASME B16.11.
📝 *Understanding Piping Material Specification (PMS):*
PMS is vital in categorizing materials for piping components. Each class within a PMS signifies components with similar material, design, and corrosion specifications. It's essential for engineers to grasp PMS, as it influences component selection and purchasing.
🔍 *Example Scenario - Forged 90 Degrees Elbow:*
In our scenario, we find the class based on the PMS category (ANO2). We specify the class (3000#) by referencing the thickness of pipe (Sch. 80) for NPS=1 ½ as per ASME B16.11.
⚙️ *Pressure Design of Wrought Fittings:*
Similarly, we determine the thickness of a wrought fitting, like a 90 degrees elbow, by referring to the PMS class (AN02). In this case, the thickness is specified as "same as pipe," and we find it to be Sch. No. 40 for NPS=4.
📚 *Conclusion and Next Steps:*
We've covered crucial aspects of specifying fittings based on ASME B31.3 standards and PMS documentation. Remember, understanding these concepts enhances your proficiency in piping engineering. Share your feedback, and stay tuned for our next session on Pressure Design of Miter Bend.
🎉 Thank you for joining us on this educational journey! 🎓