What are the regulations regarding the labeling of general-purpose valves?

Date: 2025-12-29Views: 2250

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

Valve markings:

Project

Logo

Project

Logo

1

Nominal size DN (NPS)

11

Product standard code

2

Nominal pressure PN (Class)

12

Smelting furnace number

3

Material codes for pressure-bearing components

13

Inner component material code

4

Manufacturer's name or trademark

14

Workstation number

5

Arrow indicating the direction of flow

15

Lining material code

6

Seal ring (gasket) designation

16

Quality and test marks

7

Extreme temperature (℃)

17

Inspector's signature

8

Thread designation

18

Product production license number

9

Maximum pressure

19

Year and month of manufacture

10

Manufacturer's serial number

20

Quality assessment level (QSL)

 

Note: The nominal pressure value stamped on the valve body is equal to 10 times the MPa value; when this value is located below the nominal pressure value, it is not preceded by the prefix “PN”.

Marking method:

(1) Markings for valves with a nominal size of DN50 or greater:

  1. Items 1 through 4 in the table are mandatory markings and must be affixed to the valve body.
  2. Items 5 and 6 in the table are mandatory markings only when required by a specific valve standard; they should be marked on the valve body and flange, respectively.
  3. Unless otherwise specified in the relevant valve standards, items 7 through 19 in the table are markings to be used as needed. When required, they may be marked on the valve body or on a nameplate.

(2) Markings for valves with a nominal size 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 markings for items 5 through 19 in the table shall comply with the requirements for markings 2 and 3 for nominal sizes greater than or equal to DN50.

(3) Additional symbols:

  1. Any marking in the table may be applied at different locations. For example, any marking placed on the valve body may also be repeated on a label.
  2. As long as the additional mark does not cause confusion with the marks in the table, any other mark may be added. For example: product model numbers, etc.

For pressure reducing valves, in addition to the 19 markings required for general-purpose valves, the valve body must also bear the following: date of manufacture, applicable medium, and outlet pressure.

In accordance with the provisions of GB/T 12250-2005, markings for steam traps may be affixed to the valve body or to a nameplate.

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

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