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Complete marine engine safety valve solutions
HWG Series - Explosion Relief Valve for Crankcase
The HWG Series is an explosion relief valve installed on the crankcase of main and auxiliary diesel engines. It rapidly releases abnormal pressure buildup inside the crankcase while the built-in flame arrestor prevents external flame emission, ensuring the safety of engines and crew. Designed in compliance with IACS UR M9, M10, and M66 regulations.
Related Certifications
Features
Applications
- Main engine crankcases (2-stroke and 4-stroke diesel engines)
- Auxiliary generator engine crankcases
- Compatible with MAN B&W, WinGD, Wärtsilä, Hyundai engines
- Container ships, bulk carriers, tankers, LNG carriers, VLCCs
- Offshore platform (FPSO, drillship) generator engines
Technical Details
The HWG Series explosion relief valve operates on a self-closing principle: when internal crankcase pressure exceeds the set value (0.02-0.05 bar), the spring-loaded disc opens immediately to release pressure externally, then automatically resets.
The patented Flame Arrester Unit, composed of metal mesh material, completely blocks hot flames generated during an explosion from being emitted externally. Secured through 6 patents registered in 2008, this technology prevents secondary fires caused by crankcase explosions.
IACS (International Association of Classification Societies) UR M9, M10, and M66 regulations are the international standards for crankcase explosion relief devices. The HWG Series is fully designed and certified to comply with these regulations, and holds Type Approval from major engine manufacturers including MAN B&W and WinGD for global shipbuilding projects.
Model selection: 14 models from HWG-098 (ØD2 87mm) to HWG-735 (ØD2 705mm) are available based on crankcase bore diameter. When multiple units are installed on the same crankcase, the total outflow area must be at least 115% of the maximum cylinder piston area.
Model Lineup
| Model | Outflow Area(cm²) | ØD1(mm) | ØD2(mm) | H(mm) | D(mm) | Mounting Bolt | P.C.D(mm) | Weight(kg) |
|---|---|---|---|---|---|---|---|---|
| HWG-098 | 59 | 237 | 87 | 51.6 | - | 4-M8 | 122 | 7 |
| HWG-122 | 95 | 262 | 110 | 62.6 | - | 6-M8 | 150 | 9 |
| HWG-162 | 177 | 306 | 150 | 71.3 | - | 6-M10 | 190.5 | 13 |
| HWG-173 | 201 | 319 | 160 | 78.2 | - | 6-M10 | 203 | 14 |
| HWG-204 | 284 | 351 | 190 | 86.6 | 132.5 | 6-M12 | 235 | 20 |
| HWG-224 | 346 | 371 | 210 | 96.6 | 142 | 6-M12 | 255 | 22 |
| HWG-266 | 499 | 418 | 252 | 108 | 170 | 6-M12 | 302 | 26 |
| HWG-320 | 731 | 510 | 305 | 152 | 197.5 | 6-M12 | 355 | 59 |
| HWG-345 | 830 | 556 | 325 | 164 | 214 | 6-M16 | 390 | 72 |
| HWG-420 | 1257 | 605 | 400 | 191 | 251 | 8-M16 | 465 | 93 |
| HWG-480 | 1662 | 699 | 460 | 215 | 287 | 8-M16 | 530 | 117 |
| HWG-565 | 2299 | 784 | 541 | 252.5 | 335 | 12-M16 | 615 | 153 |
| HWG-645 | 2990 | 871 | 617 | 280 | 378 | 12-M16 | 700 | 190 |
| HWG-735 | 3904 | 969 | 705 | 318 | 425 | 12-M16 | 795 | 245 |
Frequently Asked Questions
ZIC products hold type approval from 11 international classification societies.