What are the regulations for the markings on general-purpose valves?

Date: 2025-12-29Views: 539

The mandatory and optional markings for general-purpose valves are shown in the table below.

Valve markings：

sports event

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sports event

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1

Nominal Size DN (NPS)

11

Product standard code

2

Nominal pressure PN (class)

12

furnace number

3

Material designation of pressurized parts

13

Material designation of internal parts

4

Manufacturer's name or trademark

14

job number

5

Arrow for media flow direction

15

Lining Material Designator

6

Seal Ring (Gasket) Designator

16

Quality and test marks

7

Limiting temperature (°C)

17

Inspector's imprint

8

Thread code

18

Product Manufacturing License No.

9

ultimate pressure

19

Year and month of manufacture

10

Manufacturing plant number

20

Quality Satisfaction Level (QSL)

 

Note: When the nominal pressure value cast on the valve body equals ten times the megapascal (MPa) figure and is positioned below the nominal pressure value, it is not preceded by the designation “PN”.

Marking method:

(1) Valve marking for nominal sizes greater than or equal to DN50:

  1. Items 1 through 4 in the table are mandatory markings and should be affixed to the valve body.
  2. Items 5 and 6 in the table are mandatory markings only when specified in the relevant valve standards. They should be marked on the valve body and flange, respectively.
  3. Unless otherwise specified in various valve standards, items 7 through 19 in the table are optional markings. When required, they may be marked on the valve body or nameplate.

(2) Marking for valves with nominal sizes less than DN50:

  1. Items 1 through 4 in the table are mandatory markings. Whether these markings appear on the valve body or on a label is determined by the product designer.
  2. The marking of items 5 to 19 in the table shall comply with the provisions for markings 2 and 3 for nominal sizes greater than or equal to DN50.

(3) Additional markings:

  1. Any marking from the table may be affixed at different locations. For example, any marking placed on the valve body may also be duplicated on the nameplate.
  2. Any additional markings may be affixed provided they do not cause confusion with the markings on the form. For example: product model numbers, etc.

For pressure reducing valves, in addition to the 19 items specified for general valves, the markings on the valve body shall also include: date of manufacture, applicable medium, and outlet pressure.

For steam trap markings, in accordance with GB/T 12250-2005, the markings may be affixed to the valve body or displayed on a nameplate.

The marking of safety valves shall comply with the provisions of GB/T 12241-2005.

Ball valves, parallel gate valves, and plug valves shall be marked in accordance with API 6D-2014.