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Explosion Relief Valve EVN
The IEP Hoerbiger EVN 2.0 and 3.0 valves are revolutionary explosion relief valves and flameless explosion vents with a low-mass valve plate and low response pressure. This flameless vent reacts within fractions of a second in the event of an explosion. Following an explosion, it immediately seals again manually or automatically, lowering the risk of secondary explosions and costly replacement.
Special features of Hoerbiger explosion relief valves:
- No flame escape
- No air inrush thanks to quick reclosing
- Absolute tight after reclosing
- Operable in all mounting positions
- Easy to install
- Virtually maintenance-free
The standard range features an opening pressure of 0.05 bar ± 20%.
Standard range components are made of carbon steel, coated. Special materials are available on request.
Each valve is equipped with an opening detection as standard.
For specific efficiency values (%EF) mandatory for correct sizing of the necessary relief area please contact CMC Technologies Pty Ltd.
EVN in a process
IEP-Hoerbiger EVN 2.0
The Hoerbiger EVN 2.0 is certified according to EN 16009
Type | Geometric relief area [cm²] | Dimensions | Connection | Approx weight [kg] |
||||||
a [mm] |
b [mm] |
c [mm] |
d [mm] |
e [mm] |
No. of bolts |
h Thread |
k P.C.D. [mm] |
|||
266EVN 2.0 | 499 | 457 | 252 | 409 | 114 | 134 | 6 | M12 or 1/2″ | 302 | 29 |
320EVN 2.0 | 732 | 510 | 305 | 462 | 121 | 142 | 6 | M12 or 1/2″ | 355 | 37 |
420EVN 2.0 | 1260 | 625 | 400 | 579 | 150 | 165 | 8 | M16 or 5/8″ | 465 | 65 |
480EVN 2.0 | 1665 | 690 | 460 | 644 | 168 | 201 | 8 | M16 or 5/8″ | 530 | 80 |
565EVN 2.0 | 2300 | 790 | 541 | 735 | 197 | 228 | 12 | M16 or 5/8″ | 615 | 115 |
645EVN 2.0 | 2990 | 955 | 617 | 899 | 202 | 233 | 12 | M16 or 5/8″ | 700 | 160 |
735EVN 2.0 | 3905 | 970 | 705 | 910 | 222 | 260 | 12 | M16 or 5/8″ | 795 | 200 |
IEP-Hoerbiger EVN 3.0
Effective venting relief area given in the EVN 3.0 Product Manual
Type | Geom. Relief Area* | Dimensions | Approx weight | |||
cm²/in² | A mm (in) | B mm (in) | C mm (in) | D mm (in) | kg/lb | |
266EVN3.0 | 499/78 | 126 (4.96) | 442.2 (17.5) | 268.6 (10.57) | 409 (16.1) | 24/53 |
320EVN3.0 | 732/114 | 132 (5.2) | 510 (20.08) | 321.5 (12.66) | 462 (18.19) | 30/66 |
420EVN3.0 | 1260/195 | 156.5 (6.16) | 625 (24.6) | 416.6 (16.4) | 579 (22.8) | 50/110 |
480EVN3.0 | 1665/258 | 192.5 (7.58) | 690 (27.17) | 476.6 (18.76) | 644 (25.35) | 64/141 |
565EVN3.0 | 2300/365 | 213 (8.39) | 790 (31.1) | 562.2 (22.13) | 735 (28.94) | 97/214 |
645EVN3.0 | 2990/450 | 218 (8.58) | 961 (37.83) | 637.7 (25.11) | 899 (35.39 | 128/282 |
735EVN3.0 | 3905/605 | 251 (9.88) | 961 (9.88) | 727.7 (28.65) | 910 (35.83) | 137/302 |
The EVN 3.0H is an automatic reclosing, flameless explosion venting device. In case of an overpressure event (i.e a dust explosion), the valve opens and as soon the pressure falls back below the opening pressure of the valve, the valve plate closes immediately. Here are some of the features/benefits of this model
Flameless vent Type EVN3.0H- (Hygenic)
- Size, design, certification
- Field of application: reclosing flameless vent for hygienic applications
- Design: round valve with integrated flame arrester and counter flange gasket
- Material: carbon steel and stainless available
- Available size: 266 up to 735
- Type approval acc. to EN16009 similar to EVN2.0\
- Kst < 300bar.m/s
- Min. ignition energy < 2mJ
- Fibrous, melting, organic, organic synthetic dusts
- Pstat 0,05bar
- Efficiency 52-75% (pred 0,2-2,0bar)
- Max Volume 6,0m³ for 1pcs 735EVN3.0H
- Full vacuum
Differences between the EVN2.0 and the EVN3.0H
- Valve seat is not in contact with the process material
- Food grade flush profiled gasket (no gaps) – The gap-free installation allows for easy CIP cleaning of the process equipment.
- Integrated counter flange gasket
- Reduction of overall weight
NEW – Type EVN 3.0H NC
The EVN 3.0H NC is a manual re-closing flameless explosion venting device. In case of an overpressure event (i.e., a dust explosion), the valve opens and remains open until the valve plate is released manually by hand. This type of valve can be used in combination with flap valves as an explosion isolation barrier that has been tested acc. to EN16447-“Alternative testing procedure”. The chamfered shape and gap-free construction of the valve inlet prevent sedimentary product deposits. This construction allows for CIP cleaning inside the protected vessel.
Dust properties
The HOERBIGER Explosion Relief Valves type EVN 3.0H and EVN 3.0H NC were tested for the following dust groups according to EN 16009:
- Starches
- Plastics, resins, toners, sugar (melting dusts)
- Wood, MDF, flock, cellulose (fibrous dusts)
- Coal and peat
- For all above-mentioned dust groups, the following limits have to be maintained:
- Kst max 300 bar.m / s
- Pred(max) max. 2,0 bar overpressure
- Operating pressure 0,2-1,0 bar absolute pressure
Note: During normal operation the opening pressure of the valve must not be exceeded. This would lead to an unintended opening of the valve. - Static opening pressure pstat =0,05bar +/- 20%
Note: The HOERBIGER Relief valves Type EVN3.0H and EVN 3.0H NC were not tested for the use with metallic dusts.