ASME Code – Name Plate Stamping Requirements

If the markings required are stamped directly on the vessel, the minimum letter size is 5⁄16 in. If they appear on a nameplate, the minimum letter size is 5 ⁄32 in. If a nameplate is used, only the Code symbol and the manufacturer’s serial number are required to be stamped; the other information may be applied by another method, for example, etching.

For vessels having two or more pressure chambers, see Code Pars. UG-116Key: 1. Stamp National Board and the National Board number at top of plate if National Board inspection is required. If not registered with National Board, the words National Board shall be removed.

Stamp Part under Code symbol on those parts of a vessel for which partial data reports are required.

Stamp type of construction, radiographic, and post weld heat treatment status of main longitudinal and circumferential joints under Code symbol by means of the following letters:

W—arc or gas welded

RES—resistance welded

B—brazed

P—pressure welded (except resistance)

RT1—completely radiographed 100% when complete vessel satisfies full- RT and when the RT3 requirements have been applied

RT2—when the complete vessel satisfies the requirements of Code Par. UW-11(a)(5) and when the spot requirements of Code Par. UW-11(a)(5)(b) have been applied

RT3—spot-radiographed

RT4—part of vessel radiographed where none of RT1, 2 or 3 apply

HT—completely post weld heat-treated

PHT—partially post weld heat-treated

Vessels intended for special service must also be appropriately stamped separated by a hyphen after lettering of item 3 above.

L—lethal service

UB—unfired boiler

DF—direct firing

NPV—Non stationary pressure vessels

WL—Apply to nameplates of layered construction

ULT— the following markings shall be applied to  Alternative Rules for Pressure Vessels Constructed of Materials Having Higher Allowable Stresses at Low Temperature

UHT—Apply to nameplates when materials of code vessels part UHT are used.

The maximum allowable working pressure at the maximum temperature established by the designer shall be so stamped. Additionally the minimum design metal temperature at the corresponding coincident pressure shall be stamped

Pennsylvania requires shell and head thickness and head radius.

Stamp User above Code symbol if vessel is inspected by the user’s inspector.

Note: Nameplates shall be stamped with letters or numbers at least 5⁄16 in high. When vessels are designed and fabricated in accordance with Code Part ULT, the following markings shall be used in lieu of item 4 above.

Maximum Allowable Working Pressure: ______ psi at 100°F

Minimum Allowable Temperature minus:  ______°F