Passive Explosion Isolation

Passive Explosion Isolation

Passive explosion isolation relies solely on the pressure wave from the explosion . These solutions function without detection or control units. Solutions vary from diverting the explosion 180 deg , using a flap device intermittently or using a float valve that will close and shut permanently till it is manually reset again.

Brilex Passive Isolation Valves

Brilex – Type SNR Explosion Isolation Valve

Brilex – Type BPF-M Explosion Isolation – “Flap” Valve

The BPF-M isolation valve from Brilex is used as a passive decoupling element in piping, where the dust concentration is above the “Lower Explosive Limit” (LEL), i.e. combustible dust/air mixtures of Zone 20 may be supported in this piping. Under the same conditions the isolation valve is also applicable for dust/air mixtures of Zones 21 and 22. The outer part of the isolation valve may be surrounded by a Zone 22.

The isolation valve is approved as a type-tested safety system for both inorganic and organic types of dust explosion class ST1 according to guideline 94/9/EG.

Brilex – Type RSK Explosion Isolation – “Flap” Valve

The valve consists of a weighted, hinged, plate inside the main body. In normal operation, the plate is held open by the air flow through the valve. In the event of a dust explosion, the air flow is stalled and the plate will close. The plate will then be driven down hard on the valve seat by the explosion pressure.
The valve must be used in conjunction with a primary protection system on the main vessel such as an explosion vent. The RSK valve is designed for reduced explosion pressures up to 2.2 bar (up to DN400) and 1.4 bar (DN450 upwards). Therefore it should not be used in conjunction with a containment vessel which is capable of withstanding the maximum explosion pressure.
The RSK valves can be used for dust explosion hazards in the ST1 and ST2 classes.The valve must be located horizontally in the inlet duct. The minimum distance between the vessel and the valve is as follows: 2m for sizes DN160 to DN400 or 3m for sizes DN450 to DN1000.
The RSK valves are constructed from mild steel and painted (RAL3000). Unpainted versions in stainless steel 304 are available as an option.

Brilex Explosion Diverter

Brilex – Type REXS – Explosion Diverter

Brilex GmbH introduces the new Brilex REXS Explosion Diverter for safe, certified, and cost effective explosion decoupling. The REXS features an advanced design in compliance to the DIN EN 16020 Explosion Diverter standard. It has low pressure drop for organic, inorganic, and metal dusts, and is suitable for duct diameters of up to 800mm. The REXS includes an enhanced, non-fragmenting and certified Brilex DIV explosion vent.

The Brilex DIV explosion vent is suitable for Kst values up to 200 bar.m/s and is also applicable for metal dusts, for duct lengths of up to 23 meters, and a maximum reduced explosion pressure (Pred,max) from 0.3 to 0.8 bar.

Thorwesten Vent Explosion Diverters

Thorwesten Vent – Type STT – Explosion Diverter

The standard version is self reclosing. A simple additional device makes the STT diverter into a non self-reclosing explosion diverter that can be reclosed manually.


Explosion Diverters used in Coal Grinding Plant

Thorwesten Vent – Type DES – Explosion Diverter

The standard version remains open to be reclosed manually. A simple additional device provides the feature self reclosing.


Explosion Diverter used at inlet to dust collector – to prevent explosion pressure and flames propagating back to the factory

IEP Technologies Passive Isolation Valve

Whether the best explosion protection solution is suppression, venting or isolation, IEP Technologies offers the right products to meet your needs. Our system components undergo rigorous third-party testing to receive the approvals required by, for example, ATEX and NFPA. As each explosion protection threat is unique, we offer different types of explosion detectors, controls and suppressors to tailor the protection to each individual application.

IEP Technologies – ProFlapPlusII

Passive Isolation Valve

For process equipment mounted outside or close to an outside wall, explosion relief venting is a viable protection method. However, in order to protect the upstream equipment, it is vital that the protection method includes a means to mitigate propagation of flame and burning materials back upstream. This can be achieved by either using an active isolation system (chemical or mechanical), or by using a passive isolation valve. The passive explosion isolation valve is a self-actuating device, which provides a mechanical barrier to mitigate the propagation of flame and burning materials to upstream equipment. The passive isolation valve provides features unique to this style of valve, including an Accumulation Sensor, Wear Sensor and Interface Panel.

Rico Passive Isolation Valves

VENTEX ESI are explosion isolation systems after EN15089:2009D. Explosion isolation with VENTEX valves is used in systems in which combustible dusts, gases or hybrid mixes are processed.

Application area:
– pharmaceuticals industry
– chemicals / petrochemicals industry
– research laboratories
– silos, mills, drying chambers, separators
– extraction systems / etc.


Passive protection against explosions. In “single acting” ESI-E and “double-acting” ESI-D versions, the VENTEX Type 6 provides explosion protection in one ore both flow directions without requiring external energy.

– E: Single-acting without external energy / passive
– D: Double-acting without external energy /passive
– For gas, dust and hybrid mixtures
– Maximum air speed in the direction of explosion 20m/s, optional 25m/s
– Maximum air speed against the direction of explosion 35m/s
– Low response pressure
– Low pressure loss
– Short installation distance
– Simple maintenance
– Minimum downtime after an explosion
– Sizes DN100 to DN600 (other sizes available as special versions)
– No soiling caused by the closing valve



The VENTEX ESI-C Type 6 passive explosion protection valve is a check valve that does not require external energy. Its specific functionality means that it can provide explosion protection against the direction of flow.

– C: check valve without external energy /passive
– For gas, dust and hybrid mixtures
– Maximum air speed against the direction of explosion 35m/s
– Flow direction only against the direction of explosion
– Low response pressure
– Low pressure loss
– Short installation distance
– Horizontal/vertical installation possible
– Simple maintenance
– Minimum downtime after an explosion
– Sizes DN100 to DN600 (other sizes available as special versions)
– No soiling caused by the closing valve


Rico – REDEX Flap

The passive explosion isolation flap valve enables optimal protection thanks to a mechanical locking device. The REDEX Flap complies with the standard EN 16447. The flap valve is single acting and prevents the propagation of explosions opposite the flow direction.

– for applications with organic dust
– single acting
– for pull-applications
– easy maintenance
– low pressure loss
– minimal process breakdown after an explosion due to fast recommissioning
– sizes DN140 to DN400

Funktionsprinzip REDEX Flap