Related Clues:

• Measure of length
• Pipe fitter's union?
• Architectural annex
• Architectural wing, perhaps
• Connecting pipe
• Letter after kay
• Pipe fitter's joint
• Right-angled wing
• Wing that can't flap
• A ___ of plovers
• A kind of add on
• Corner shape
• 90 degree pipe joint
• Connection with a bend
• Supplementary structure