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In-Line Deflagration Flame Arrester for biogas, sewage gas and landfi ll gas, concentric design, bidirectional, endurance burning proof (under atmospheric conditions)

  • state of the art design for bio-, sewage- and landfill gas applications
  • modular design
  • the individual FLAMEFILTER® can be quickly removed and installed
  • threaded connection for direct mounting into pipeline
  • bidirectional flame transmission proof design
  • provides protection against deflagrations and endurance burning under atmospheric conditions for explosion group IIA1- methane
  • cost efficient spare parts

Function and Description

The PROTEGO® FA-G-IIA1-P2.2 in-line deflagration flame arrester was specially developed for bio-, sewage- and landfill-gas applications. The compact design of the PROTEGO® FA-G makes it the state of the art technology for installation in pipes with diameters of ½” up to 2”. The devices are installed with minimal distance to the burner to prevent flashback in to the fuel feed lines. When installing the deflagration flame arrester, make sure that the distance between potential ignition sources and the location of the installed device, does not exceed the L/D ratio (pipe length/pipe diameter), for which the device was approved. As per EN ISO 16852 the L/D ratio is limited to (L/D) max ≤ 50 for deflagration flame arresters of explosion group IIA1.

The in-line deflagration flame arrester is symmetrical and offers bidirectional flame transmission protection. The device consists of two housing parts (1) and two FLAMEFILTER® (2) in the center.

The PROTEGO® FA-G-IIA1-P2.2 flame arrester protects against deflagrations and endurance burning (under atmospheric condition) and short time burning for 1 min. for the maximum operating conditions of explosion group IIA1 - methane.

PROTEGO® FA-G devices for substances of explosion groups IIA, IIB3 and IIC (NEC groups D, C, and B) are shown on separate pages.

The standard design can be used up to an operating temperature of +60°C / 140°F and an absolute operating pressure up to 2.2 bar / 31.9 psi.

Type-approved in accordance with the current ATEX Directive and EN ISO 16852 as well as other international standards.


To select the nominal size (DN), use the flow capacity charts on the following pages

DNG ½G ¾G 1G 1 ¼G 1 ½G 2
Dimensions in mm / inches, SW= width across flats

Material selection

HousingStainless SteelHastelloy
FLAMEFILTER®*Stainless SteelHastelloy
* the FLAMEFILTER® is also available in the materials Tantalum, Inconel, Copper, etc. when the listed housing materials are used. Special materials upon request

Selection of explosion group

MESGExpl. Gr. (IEC / CEN)
≥ 1,14 mmIIA1
Special approvals upon request

Selection of max. operating pressure

Expl. GrDNG ½G ¾G 1G 1 ¼G 1 ½G 2
Pmax = maximum allowable operating pressure in bar / psi absolute, higher operating pressure upon request

Specification of max. operating temperature

≤ 60°C / 140°FTmaximum allowable operating temperature in °C
higher operating temperatures upon request

Type of connection

Pipe thread DIN ISO 228-1DIN
other types of thread upon request

Design Types and Specifications

There are three different designs:

Basic in-line deflagration flame arrester

(G ½'' to 2'')

FA-G - –

In-line deflagration flame arrester with integrated

temperature sensor* for additional protection

against short-time burning from one side

(G 1½'' to 2'')

FA-G - T

In-line deflagration flame arrester with two

integrated temperature sensors* for additional

protection against short-time burning from both

sides (G 1½'' to 2'')


Additional special devices available upon request
*Resistance thermometer for device group II, category (1) 2 (GII cat. (1) 2)

Flow Capacity Chart

The flow capacity charts have been determined with a calibrated and TÜV certified flow capacity test rig. Volume flow V in (m³/h) and CFH refer to the standard reference conditions of air ISO 6358 (20°C, 1bar). For conversion to other densities and temperatures refer to Sec. 1: “Technical Fundamentals”.