API 510 API 510 Welding Procedures and Qualifications 2

Question 1

What is the primary purpose of post-weld heat treatment (PWHT) in pressure vessel repairs?

Accepted Answer

Stress relief and improved resistance to stress corrosion cracking

Answer

PWHT is primarily performed to relieve residual welding stresses and improve resistance to stress corrosion cracking and hydrogen embrittlement.

Question 2

According to ASME Section VIII Div. 1, PWHT is mandatory for carbon steel welds when the nominal thickness of the base metal exceeds what value?

Accepted Answer

1-1/2 inches (38 mm)

Answer

ASME Section VIII Div. 1 requires mandatory PWHT for P-1 carbon steel when base metal thickness exceeds 1-1/2 inches.

Question 3

Which type of weld joint is used when only one side of a pressure vessel shell is accessible for repair welding?

Accepted Answer

Single-welded butt joint with backing strip

Answer

When access is limited to one side, a single-welded butt joint with a backing strip is commonly used to achieve full penetration and adequate root quality.

Question 4

Under API 510, an authorized inspector must review and accept which document before repair welding begins on a pressure vessel?

Accepted Answer

The repair plan and applicable WPS/PQR

Answer

The authorized inspector must review and accept the repair plan and applicable Welding Procedure Specifications (WPS) and Procedure Qualification Records (PQR) prior to commencing repair work.

Question 5

When performing a temper bead welding technique, what is its primary advantage over conventional PWHT?

Accepted Answer

It refines the heat-affected zone grain structure without furnace PWHT

Answer

Temper bead welding uses controlled deposition of successive weld beads to refine and temper the heat-affected zone, achieving stress relief without furnace PWHT.

(API 510) Certified Pressure Vessel Inspector Practice Test

(API 510) Certified Pressure Vessel Inspector Practice Test

API 510 API 510 Welding Procedures and Qualifications 2