API 510 Repair, Alteration & Rerating Procedures 4

Question 1

According to API 510, weld overlay (cladding restoration) on a corroded vessel shell is classified as a:

Accepted Answer

Repair requiring WPS qualification and authorized inspector involvement

Answer

Cosmetic repair not subject to code requirements

Answer

Minor maintenance activity exempt from PWHT requirements

Answer

Structural alteration requiring full vessel rerating

Question 2

A pressure vessel owner wants to lower the MAWP of a vessel (rerate downward). Under API 510, this:

Accepted Answer

Is generally straightforward and requires updating the nameplate and records

Answer

Requires the same engineering rigor as a rerating upward

Answer

Is not permitted under any circumstances

Answer

Requires a full hydrostatic test at the new lower pressure

Question 3

When a repair is made by welding on a vessel in hydrogen service, which additional concern must be addressed?

Accepted Answer

Hydrogen embrittlement risk and the need for bake-out procedures before welding

Answer

The use of stainless steel filler metal only

Answer

A minimum preheat of 400°F regardless of material

Answer

Mandatory radiography of the entire vessel shell

Question 4

Under API 510, which document establishes the minimum requirements for repair organizations performing welded repairs on pressure vessels?

Accepted Answer

The National Board Inspection Code (NBIC)

Answer

ASME B31.3

Answer

API RP 579

Answer

API Standard 653

Question 5

After a repair, the inspector records the work on which form when using the National Board program?

Accepted Answer

NB Form R-1 (Report of Repair)

Answer

ASME Form U-1 (Manufacturer's Data Report)

Answer

API Form 510-A (Inspection Record)

Answer

OSHA Form 300 (Incident Log)

Question 6

When performing a rerating calculation for a cylindrical shell under internal pressure using API 510, the formula used is based on:

Accepted Answer

ASME Section VIII Division 1 thickness and stress equations for the shell

Answer

The original material mill certification only

Answer

A simplified factor of 4:1 safety ratio applied to the test pressure

Answer

The original purchase order specifications

Question 7

A repair organization proposes to use a weld procedure not qualified to the current code edition for a vessel repair. Under API 510, this is:

Accepted Answer

Unacceptable; all WPS must be qualified per an applicable welding code

Answer

Acceptable if the welder has 10+ years experience with that procedure

Answer

Acceptable for minor repairs under 6 inches in length

Answer

At the discretion of the plant maintenance supervisor