Relief Valves for Crankcases

Reliable explosion protection for marine engines

  • Reliable flameless pressure relief
  • No direct shut-down of the engine
  • Maintenance-free and operational for many years

HOERBIGER relief valves for crankcases are used primarily in ships’ engines. They comply with all current regulations for onshore and offshore applications.

The compact HOERBIGER relief valves are ATEX-certified (EVN model series) and UR M66 approved by all IACS Classification Societies (EVO and EVS model series). Because of the low-mass valve plate and low response pressure, they react within fractions of a second in the event of an explosion. Thanks to the integrated flame arrester, they ensure flameless pressure relief. Following an explosion, they immediately close again and are sealed, lowering the risk of secondary explosions.

After an explosion, the valves provide reliable safety until the next opportunity for machine shutdown. They are virtually maintenance-free and offer reliable explosion pressure relief—for many years.

Technical data

Diameter inches millimeters
EVN 3.8 to 28.9 98 to 735
EVO 3.8 to 10.4 98 to 266
EVS 6.8 to 28.9 173 to 735
**Geometric venting cross-section inches²** centimeters²
EVN 9.2 to 605.2 59.4 to 3905
EVO 9.2 to 77.3 59.4 to 499
EVS 31.1 to 572.4 201 to 3693