Technical regulations and scope of application for gate valves according to EN 1984 standard
This standard establishes strict operational requirements for steel gate valves manufactured by casting, forging, or welding. The document covers valves with various connection types to the pipeline: flanged, butt-welding (BW), socket-welding (SW), and threaded (NPT/GAS).
The EV Group China specification is focused on the industrial use of gate valves in critical process units. The use of products in specialized environments is permitted provided they comply with additional industry standards.
Nominal diameters and sizes
The range covers the following nominal sizes (DN):
- DN8, DN10, DN12, DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80, DN100, DN125, DN150, DN200, DN250, DN300, DN350, DN400, DN450, DN500, DN600, DN700, DN750, DN800, DN900, DN1000.
- DN750 is applicable exclusively for gate valves with Class pressure rating.
- Sizes DN8 and DN12 are not intended for use in flanged versions.
- Gate valves with threaded and socket-welded connections are limited to the DN8 – DN65 range.
Nominal pressure classification
| Connection type | PN-rating | Class-rating |
|---|---|---|
| Flanged | PN10–PN100 | Class 150–600 |
| Butt-welding | PN10–PN100 | Class 150–600 |
| Socket-welding / Threaded | PN10–PN100 | Class 600, 800 |
Note 1: Socket-welded and threaded gate valves are not typically produced in PN10–PN40 pressure classes.
Note 2: Class 800 is an intermediate standard adopted for small-bore valves with threaded or socket ends.
Requirements for materials and components
Materials for primary load-bearing elements (body, bonnet, cover) must strictly comply with prEN 1503-1 and prEN 1503-2 specifications. Internal components in contact with the process medium are selected based on corrosion resistance, which must be equal to or better than the body material.
Key components requiring composition control:
- Stem (manufactured by forging or rolling; minimum chromium content — 13% to ensure anti-corrosion properties).
- Gate seal rings.
- Body seat.
- Back seat (mandatory for DN50 and above).
Geometric parameters
Face-to-face lengths and connection dimensions are determined by the following standards:
- Flanged gate valves (PN): EN 558-1.
- Flanged gate valves (Class): EN 558-2.
- Butt-welding gate valves: EN 12982.
- Threaded and socket-welding gate valves: regulated by the technical specifications of the specific manufacturer (EV Group China).