The Protego LH/AD is an end-of-line deflagration flame arrester engineered to prevent flame transmission caused by atmospheric deflagrations. It’s typically installed on vent lines of non-pressurized vessels or plant equipment, where vapor is discharged only for short durations. Equipped with a robust weather hood and protection screen, this unit blocks flame ingress while shielding the flame arrester element from environmental elements like debris, birds, and nesting animals.
Weather hood with protection screen
Atmospheric deflagration flame stopping
Designed for non-pressurized vents
IIA, IIB3, IIC
Atmospheric
Modular FLAMEFILTER® with replaceable discs
EN 1092-1, Form B1 ASME B16.5 CL 150 R.F. (others on request)
DN 50 (2″) to DN 800 (32″)
Up to +60 °C / 140 °F
Certifications ATEX compliant, EN ISO 16852
DN Size
a (mm/in)
b (mm/in)
c IIB3 (mm/in)
c IIC (mm/in)
50 / 2″
100 / 3.94
200 / 7.87
175 / 6.89
185 / 7.28
100 / 4″
200 / 7.87
295 / 11.61
220 / 8.66
235 / 9.25
150 / 6″
300 / 11.81
550 / 21.65
260 / 10.24
270 / 10.63
300 / 12″
400 / 15.75
600 / 23.62
340 / 13.39
350 / 13.78
800 / 32″
1200 / 47.24
1600 / 62.99
550 / 21.65
560 / 22.05
Designed for storage tanks, vent stacks, and low-pressure vessels, especially in industries like chemical, petrochemical, waste treatment, and flammable liquid storage where intermittent venting to atmosphere must be protected from external ignition risks.
Effective for vapors and gases in explosion groups IIA, IIB3, and IIC. Suitable where endurance burning is excluded. Special certifications available for carbon disulfide (CS₂) applications.
Protects against external atmospheric ignition
No pressure drop across the vessel
Prevents ingress of foreign materials or animals
Maintenance-friendly and long lifecycle
Certified for hazardous environments with high safety demands
Design Variants:
LH/AD – Standard version for general deflagration protection
LH/AD-CS₂ – Special version for carbon disulfide (CS₂) vapors
Custom designs – Available on request for specific applications
Optional Add-ons:
Special materials for housing and flame filters (e.g., Stainless Steel, custom alloys)
Larger or non-standard connection sizes
High-temperature approved designs
From forging and casting to machining, assembly, and testing — every step is managed under one roof to ensure consistent quality, faster lead times, and zero compromise.
Get in touch with our team for additional information on product pricing, technical data, project support and more.
