Piping Pipe Welding and Fabrication 2

Question 1

What is the difference between a socket weld and a butt weld fitting?

Accepted Answer

Socket welds use a fillet weld at the outside of the fitting; butt welds use a groove weld joining pipe ends directly

Answer

Socket weld fittings slip over the pipe end and are sealed with a fillet weld, while butt weld fittings are beveled to match the pipe end for a full-penetration groove weld.

Question 2

According to ASME B31.3, what is the standard gap (crevice) to be left when making a socket weld?

Accepted Answer

Approximately 1/16 inch (1.6 mm) gap before making the weld

Answer

ASME B31.3 requires approximately 1/16 inch gap in socket welds to allow for thermal expansion of the pipe end during welding and operation.

Question 3

What nondestructive examination (NDE) method is specifically used to detect surface-breaking cracks in ferromagnetic pipe welds?

Accepted Answer

Magnetic Particle Testing (MT)

Answer

Magnetic Particle Testing (MT) detects surface and near-surface discontinuities in ferromagnetic materials by applying a magnetic field and iron particles.

Question 4

What is the purpose of a Procedure Qualification Record (PQR)?

Accepted Answer

To document the test results that support and qualify a WPS

Answer

The PQR records the actual welding variables used and the mechanical test results from a test weld, demonstrating that the WPS procedure produces acceptable welds.

Question 5

In pipe fabrication, what is 'spool' fabrication?

Accepted Answer

Pre-fabricating pipe assemblies (sections with fittings and flanges) in a shop for field installation

Answer

Pipe spools are pre-fabricated assemblies made in controlled shop conditions, then transported to the field and connected by field welds, improving quality and efficiency.

Piping Practice Test

Piping Practice Test

Piping Pipe Welding and Fabrication 2