Technical information / Valve dimensions / API 594
Valve dimension standard
API 594 · TYPE A
Face-to-face dimensions of wafer and lug check valves
A wafer check valve is clamped between two pipe flanges with gaskets; L is the length between the two gasket faces of the body.
| NPS | DN | 150Class | 300Class | 600Class | 900 †Class | 1500 †Class | 2500 †Class | s16EN 558 |
|---|---|---|---|---|---|---|---|---|
| 2" | DN50 | 60 | 60 | 60 | 70 | 70 | 70 | 43 |
| 2 1/2" | DN65 | 67 | 67 | 67 | 83 | 83 | 83 | 46 |
| 3" | DN80 | 73 | 73 | 73 | 83 | 83 | 86 | 64 |
| 4" | DN100 | 73 | 73 | 79 | 102 | 102 | 105 | 64 |
| 6" | DN150 | 98 | 98 | 136 | 159 | 159 | 159 | 76 |
| 8" | DN200 | 127 | 127 | 165 | 206 | 206 | 206 | 89 |
| 10" | DN250 | 146 | 146 | 213 | 241 | 248 | 254 | 114 |
| 12" | DN300 | 181 | 181 | 229 | 292 | 305 | 305 | 114 |
| 14" | DN350 | 184 | 222 | 273 | 356 | 356 | — | 127 |
| 16" | DN400 | 191 | 232 | 305 | 384 | 384 | — | 140 |
| 18" | DN450 | 203 | 264 | 362 | 451 | 468 | — | 152 |
| 20" | DN500 | 219 | 292 | 368 | 451 | 533 | — | 152 |
| 24" | DN600 | 222 | 318 | 438 | 495 | 559 | — | — |
| 30" | DN750 | 305 | 368 | 505 | — | — | — | — |
| 36" | DN900 | 368 | 483 | 635 | — | — | — | — |
| 42" | DN1050 | 432 | 568 | 701 | — | — | — | — |
| 48" | DN1200 | 524 | 629 | — | — | — | — | — |
Notes
- This table has been compiled by Emsal from the relevant standards. For the full text of the standard, refer to API.
- Type A: wafer, lug and single-piece body check valves — this table. Type B: double-flanged check valves; their face-to-face dimensions follow the check valve column of ASME B16.10.
- The Class 150, 300 and 600 values (NPS 2–24) are identical in three independent sources. The Class 900–2500 columns marked † are based on a single source.
- NPS 5 is not in the standard; some manufacturers use their own length for this size (e.g. 86 mm).
- The length tolerance is according to ASME B16.10 up to NPS 24 and ±3 mm for larger sizes.
- EN 558 series 16 is the short length for PN-rated dual plate check valves in Europe and is noticeably shorter than API 594. The two are not interchangeable; state which one you need when ordering.
- Accuracy and currency are not guaranteed; use the current edition of the standard for design and purchasing decisions. How the library is compiled →
Our products
| 1 | Dual plate check valve: EN 558 series 16 length (DN50–600) Dual plate check valve → |
| 2 | Wafer check valve: single disc, slim body; manufacturer's length outside these tables Wafer check valve → |