🔍 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)