ISOV - Air Intake Shutoff Valve
Stands Up for Safety Since 1990

About ISOV

The ISOV valve is a positive spring operated air intake shutoff valve that provides emergency overspeed shutdown of a diesel engine. Mechanical failure or the presence of combustible vapors like hydrocarbons in the engine’s intake system may cause the engine to overspeed beyond control, causing severe damage to the engine or even explosion.


We offer the most comprehensive and diverse line of positive air shutoff valves.
In addition, our installation and activation kits are specifically engineered for your application.

ISOV manufactures engine overspeed shutdown devices for every application, of which some typical are listed below:

Drilling Rigs (Onshore & Offshore)
Drilling Support Equipment
Well Servicing Equipment
Refinery Support Equipment
Bulk Haulers and Tankers
Material Handling
Generator Sets

Air Compressors and many more


Special Features of ISO Valve

Special Features of ISO Valve

Material & Finishing

ISOV castings and internal parts can be produced using non-standard materials to meet specific customer requirements, particularly for the OEM market. This flexibility is necessary to address the demands of high temperature inlets and challenging climatic conditions. For instance, ISOV castings can be manufactured using stainless steel or even hastelloy if needed. Moreover, various surface treatments like anodizing and powder coating are also offered to enhance the quality and durability of the products.

Custom Flanges & Adapters

At ISOV we produce custom flanges to make it compatible to a wide variety of inlet pipings. We do this for new engines, as well as retrofit in existing engines regardless of make or age.
Typical air inlets can be:

  • Hose and Clamp Connection
  • O-ring Connection
  • Marman Flange
  • Elbow and/or Flangebolt Connection


Special attention is required for electrical components in Offshore and Marine Grade Constructions.

The solenoids employed in ISOV valves are produced and examined according to DIN VDE0580 standards, featuring a plug and socket connection conforming to DIN-175301-803 specifications. This design guarantees secure and dependable functionality.

Position Switch

To monitor the opening and close condition of an ISOV, two types of switches are used, Photoelectric (type D1) and Electromechanical (D2).
D2 type switches are required for Marine and Offshore applications and have an IP65 rating. Alternatively Explosion Proof switches are used for hazardous area applications.

REMCON Remote Control

REMCON is an ISOV Valve intended for remote opening and is fitted with either an electric or a pneumatic operator to provide maximum flexibility. Depending on engine intake configuration / piping we offer both a side and a top mounted remote control operator to avoid interference with other engine parts (refer to Ordering Codes on Page 4).
Remote opening of valves is an outcome in applications such as unmanned platforms, remote engine rooms and in arctic conditions. REMCON is also used for large size in which manual opening requires excessive force and / or difficult accessibility. ISOV’s unique Remote Control is designed to fit on bores from 100mm up to 508 mm.
REMCON Electronic controllers developed by ISOV, is a rail mounted module which can be integrated in any existing control panel.

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