🔍 Key Concepts

• Differences in how socket weld, threaded, and van stone flanges connect to the pipe • Look closely at whether the pipe end is inserted into a recess, screwed in with threads, or loose against a flange • How the weld location and shape in figure D compares with the other figures (A, B, C, E)

💭 Think About

• In illustration D, is the pipe end sitting inside a counterbored recess, or is it flush with the face of the flange? • Do you see any sign of internal or external threads, or does the joint rely entirely on a fillet weld at the shoulder? • Compare D to the figure that clearly shows a pipe sliding loosely against a backing flange – which type does that represent, and how is D different from it?

✅ Before You Answer

• Verify whether the pipe OD (outside diameter) is a close fit inside a socket in the flange in view D • Check if there are threads drawn anywhere at the joint in view D; if there are none, eliminate any choice that requires threads • Confirm that in D the flange is fixed to the pipe by welding, rather than being a loose piece that can rotate independently of the pipe (as with a van stone flange)