From Pressure Vessels : ASME Code Simplified, Eighth Edition


An attempt is made in this chapter to assist those wishing to find specific information quickly without having to wade through the large fund of specifications and recommendations encompassed by the Code. Figures and tables outline designs, materials, or performance requirements, indicate conditions for which precautions are necessary, and list Code paragraphs to be read for the proper information. Experience has proven that many of these items are often overlooked. Also included is a handy reference chart (Fig. 2.1) that graphically illustrates the various parts of a pressure vessel and the Code paragraphs that apply to each. Table 2.1 lists the various classes of materials from Section VIII, Division 1, the covering Code section part, applicable references for the stress value tables found in Section II, Part D, and additional helpful hints. It should be remembered, however, that there is no substitute for reading the Code itself.

Figure 2.1: Reference chart for ASME Pressure Vessel Code, Section VIII, Division 1.
Table 2.1: Classes of Materials
Material Covering Code part Applicable Code stress value tables Remarks

Carbon and low-alloy steels


Code Section II, Part D, Table 1A

Basis for establishing stress values Code Appendix P, UG-23

Low-temperature service requires use of notch-tough materials Code Pars. UCS-65, UCS-66, UCS-67, UCS-68, UG-84

Code Figs. UCS-66, UCS-66.1, UCS-66.2

In high-temperature operation, creep strength is essential

Design temperature Code Par. UG-20

Design pressure Code Par. UG-21, Fn. 8

Products & Services
Rupture Discs and Burst Discs
Rupture discs and burst discs are designed to open and relieve overpressure, high temperature, or vacuum conditions at a predetermined differential pressure or specific temperature. They may be thermally or mechanically actuated.
Welding Alloys
Welding alloys are used to melt and fuse pieces of metal together.
Tank Heads
Tank heads are the end caps on cylindrically-shaped pressure vessels. They generally comply with ASME standards or similar codes because of the high pressures they must withstand for use with gas storage tanks, driving cylinders, distillation towers, and reactors.
Boiler and Pressure Vessel (BPV) Services
Boiler services include repair, rebuilding, maintenance and installation of boilers. They may also provide cleaning, calibration, condition assessment, field inspection, failure analysis, and part replacement services.
Rolled Rings
Rolled rings (or seamless forged rings) are hollow metal cylinder shapes used as starting stock blanks for wheels or rail tires, housings, bearings, gears, valve seats, ring gaskets and couplings.

Topics of Interest

Requirements for Establishing Design Thickness Based on Degree of Radiography (Code Pars. UW-11 and UW-12) The requirements based on the degree of radiographic examination of butt welds in pressure...

Use of Simplified External-Pressure Cylindrical Shell Thickness Charts (Figs. 2.7 and 2.8) These charts give at a glance the shell thickness required for carbon-steel and type 304 stainless steel...

Shop Inspection An authorized inspector s first step in the shop inspection of Code vessels is to review the design. It is the manufacturer s responsibility to submit drawings, calculations, and the...

Allowable Pressure, Pitch, and Thickness Areas of flat surfaces under internal pressure which are not supported have the tendency while under pressure to deform, bulge, and try to form a circle. An...

9.6 PRESSURE SETTINGS AND DESIGN BASIS Unfired steam boilers, that is, nominally termed "waste heat boilers" or "heat exchangers", which generate steam by heat interchange with other fluids (see ASME...