Welding and Joining Techniques Flashcards
7 cards from real PIPEFITTER practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Welding and Joining Techniques flashcards as text
When qualifying a welding procedure specification (WPS) under ASME Section IX, changing the base metal P-Number typically requires:
Answer: Requalification of the procedure with a new PQR
Under ASME Section IX, a change in base metal P-Number is an essential variable that requires requalification of the welding procedure through a new Procedure Qualification Record (PQR).
In GTAW (TIG) pipe welding, the high-frequency arc start is preferred over scratch start primarily because:
Answer: It prevents tungsten contamination of the weld pool
High-frequency arc starting allows the arc to initiate without touching the tungsten to the base metal, preventing tungsten inclusions in the weld and preserving electrode geometry.
What is the correct root opening (gap) typically used when fitting up Schedule 40 carbon steel pipe for SMAW butt welding without a backing ring?
Answer: 1/16 to 3/32 inch
A root opening of 1/16 to 3/32 inch allows full penetration of the root pass in open-root SMAW pipe welding without excessive burn-through.
During pipe welding inspection, a 'hi-lo' gauge is used to measure:
Answer: The mismatch (internal misalignment) between pipe ends
A hi-lo gauge measures the internal offset between two pipe ends being joined; excessive hi-lo creates stress concentrations and is limited by welding codes.
Which NDE method is most effective for detecting lack-of-fusion defects in a pipe weld that is inaccessible from the inside?
Answer: Phased array ultrasonic testing (PAUT)
Phased array ultrasonic testing (PAUT) can detect internal volumetric defects including lack of fusion from the pipe's outer surface without requiring internal access.
When making a socket weld connection, AWS D10.11 recommends that the pipe be inserted into the fitting and then pulled back approximately:
Answer: 1/16 inch before welding
Pulling the pipe back 1/16 inch from the socket bottom allows for thermal expansion during welding and prevents crevice corrosion from a zero-gap fit.
What is the maximum allowable undercut depth on a completed pipe weld per most ASME B31.3 process piping requirements?
Answer: 1/32 inch or 10% of wall thickness, whichever is less
ASME B31.3 limits undercut to 1/32 inch or 10% of the nominal wall thickness, whichever is less, to preserve the structural integrity of the pipe wall.