ARTICLE KR-4MARKING AND STAMPING REQUIREMENTS

KR-400 MARKING

KR-401 Marking of Pressure Relief Valves

Each pressure relief valve shall be plainly markedby the Manufacturer or Assembler with the requireddata in such a way that the markings will not beobliterated in service. The markings shall be locatedon a plate securely fastened to the valve. Small valves(less than NPS1⁄2 inlet) may have the nameplateattached with a chain or wire. See KS-130 for methodsof application. The marking shall include:

(a) the name or identifying trademark of the Manufac-turer and/or Assembler, as appropriate

(b) Manufacturer’s or Assembler’s design or typenumber

(c) valve inlet size, in.(d) set pressure, psi(e) flow capacity, SCFM of air (60°F and 14.7 psia)

(16°C and 101 kPa), or gal /min of water at 70°F(21°C), if the pressure relief valve is to be tested tohave a certified flow capacity; see KR-122 and KR-123(b). If the pressure relief valve is not flow capacitytested and certified, the flow capacity shall be stamped“NONE.”

NOTE: In addition, the Manufacturer /Assembler may indicate theflow capacity in other fluids (see KR-530).

(f) year built or, alternatively, a coding may bemarked on the valve such that the valve Manufacturer /Assembler can identify the year built

(g) ASME Code symbol as shown in Fig. KR-401(h) Use of the Code symbol stamp by an Assembler

shall indicate the use of original, unmodified parts instrict accordance with instructions of the Manufacturerof the valve. The nameplate marking shall include thename of the Manufacturer and the Assembler, and theCode symbol stamp shall be that of the Assembler.

KR-402 Marking of Rupture Disk Devices

Every rupture disk shall be plainly marked by theManufacturer in such a way that the marking will not

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FIG. KR-401 OFFICIAL SYMBOL FOR STAMP TODENOTE THE AMERICAN SOCIETY OFMECHANICAL ENGINEERS’ STANDARD

be obliterated in service and will not interfere withthe function of the disk. The marking may be placedon the flange of the disk or on a metal tab permanentlyattached thereto. Alternatively, the marking may beplaced on a metal tag packaged with each individualrupture disk, to be attached to the holding fixture atassembly; see KR-201 for additional requirements. Themarking shall include the following:

(a) the name or identifying trademark of the Manufac-turer

(b) Manufacturer’s design, type number, or drawingnumber

(c) lot number

(d) material

(e) size, in.

(f) stamped burst pressure, psig

(g) coincident disk temperature, °FItems (a), (b), (d), and (e) shall also be marked on

the rupture disk holder. See also KR-201.In lieu of marking all of the listed items on the

flange or tab of each rupture disk, the marking mayconsist of the stamped bursting pressure and a Manufac-turer’s coding number sufficient to identify each diskwith a Certificate which includes the required informa-tion, if such a Certificate is supplied for each lot ofrupture disks.

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KR-403 2001 SECTION VIII — DIVISION 3 KR-410

KR-403 Marking of Pressure Relief Valves inCombination With Rupture DiskDevices

Pressure relief valves in combination with rupturedisk devices shall be marked with the flow capacityestablished in accordance to KR-220, in addition tothe marking of KR-401 and KR-402. The marking maybe placed on the valve or on a plate or plates securelyfastened to the valve. The marking shall include themarking required by KR-401(a) through (g) and the

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specific details of the rupture disk device so that therupture disk device is uniquely identified and specified.

KR-410 USE OF CODE SYMBOL STAMP

Each pressure relief valve to which the Code symbolis to be applied shall be fabricated by a Manufacturerwho is in possession of a Code symbol stamp (seeFig. KR-401) and a valid Certificate of Authorization,obtainable when the conditions of Article KS-2 havebeen met.

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