API 510 Pressure Vessel Design & Fabrication Standards 4

Question 1

A torispherical (flanged and dished) head is being designed per ASME VIII-1 UG-32(e). What is the crown radius (L) used in the minimum thickness formula?

Accepted Answer

Equal to the inside diameter of the shell

Answer

Per UG-32(e), for a standard torispherical head, the crown radius L shall not be greater than the outside diameter of the skirt, and for a standard head equals the shell inside diameter.

Question 2

Per ASME Section VIII Div. 1, what is the minimum shell thickness (excluding corrosion allowance) allowed for pressure vessels under internal pressure?

Accepted Answer

1/16 in. (1.6 mm)

Answer

UG-16(b) specifies that, except for certain heat exchanger tubes, no shell or head shall be less than 1/16 in. (1.6 mm) thick after forming.

Question 3

In ASME Section VIII Div. 1 fabrication, what is the maximum allowable out-of-roundness (peaking/banding) for a cylindrical shell per UG-80?

Accepted Answer

The difference between max and min diameters shall not exceed 1% of nominal diameter

Answer

UG-80 requires that the difference between maximum and minimum inside diameters at any cross-section shall not exceed 1% of the nominal inside diameter.

Question 4

Which ASME Section VIII Div. 1 table provides the allowable stress values (S) for carbon and low alloy steel materials used in vessel design calculations?

Accepted Answer

Table UCS-23

Answer

Table UCS-23 (Section II Part D) lists the maximum allowable stress values for carbon and low alloy steel materials used in VIII-1 pressure vessel design.

Question 5

A nozzle reinforcement calculation per ASME VIII-1 UG-37 is required to show that the area removed by the opening is replaced within a defined reinforcement zone. What width defines the reinforcement zone on each side of the nozzle centerline?

Accepted Answer

The inside diameter of the opening (d)

Answer

Per UG-40, the reinforcement zone width on each side of the nozzle axis equals the larger of the nozzle inside diameter (d) or (Rn + tn + t) but the basic zone half-width is d, the finished inside diameter of the opening.

(API 510) Certified Pressure Vessel Inspector Practice Test

(API 510) Certified Pressure Vessel Inspector Practice Test

API 510 Pressure Vessel Design & Fabrication Standards 4