Weldability of a Metal

● Metallurgical Capacity

 Parent metal will join with the weld metal without formation of deleterious constituents or alloys.

● Mechanical Soundness

 Joint will be free from discontinuities, gas porosity, shrinkage, slag, or cracks.

● Serviceability

 Weld is able to perform under varying conditions or service (e.g., extreme temperatures, corrosive environments, fatigue, high pressures, etc.).

INSPECTION FOR SPECIFIC TYPES OF CORROSION AND CRACKING

Each owner/user should provide specific attention to the need for inspection of piping systems that are susceptible to the following specific types and areas of deterioration (API RP 570) :

a. Injection points.

b. Deadlegs.

c. Corrosion under insulation (CUI).

d. Soil-to-air (S/A) interfaces.

e. Service specific and localized corrosion.

f. Erosion and corrosion/erosion.

g. Environmental cracking.

h. Corrosion beneath linings and deposits.

i. Fatigue cracking.

j. Creep cracking.

k. Brittle fracture.

l. Freeze damage.