Flame Arrester

SEWON has been developed so many kinds of flame arrester including detonation type as a safety device for plants and vessels.

Flame arrester is to protect the safety equipment from flame, by being equipped into the pipe lines, gas duct lines and vent lines of the tank where
inflammable gas is stored, and is a very important device to prevent the flame occurred due to explosion, and ignition that is happened when inflammable
gas is changed up to the temperature of flashing point owing to the influence of operation of equipment or surrounding environment, etc..

There are several types of flame arrester such as crimped ribbon arresters, parallel plate arresters, pebble arresters, hydraulic arresters, wire screen
arresters, wire packed arresters and sintered arresters, but crimped ribbon arresters are most commonly used. Each type has its own characteristics
and they are not necessarily all suitable for the same service.

SEWON crimped metal flame arresters are safety devices designed to stop the propagation or spread of flames through flammable gas or vapor mixtures
in pipelines. They prevent flame entering or leaving plant and can confine flame propagation to within certain equipment. Flame arresters are passive
devices, operating automatically and normally have no moving parts.

When gas or vapor mixtures ignite, flame arresters prevents further propagation by absorbing and dissipating heat from the burning gas or vapor
on one side of arresters lowering the temperature of the combustion products to below the auto ignition point of the gas on the opposite side.
This is achieved as the hot gasses give up their heat to the cell walls on passing through the crimped metal arrester element.

Selection Criteria

Critical infomation needed for. the proper application of flame and detonation arresters
Chart 1shows the effect of increases in pipe length on flame front speed and pressure. A 4.3% propane/air mixture is ignited in a 2" pipe.
20 feet of straight 2" pipe produces a flame speed of 550 feet per second.
When this piping length is increased to only 36 feet, a flame speed of 6400 feet per second is recorded. This is a clear detonation(the movement of
a flame through a gas or vapor within a medium at the speed of sound in that medium). A standard vent-line/in-line flame arrester can be rendered
ineffective.

As we see in Chart2, 6.25 feet of straight piping will yield a flame speed of 180 feet per second. Introduction of only 90 degree bend and 16 feet of
straight piping accelerates the flame front to a detonation. Not taking these bends, irregularities or obstructions into consideration can easily lead
to a misapplication of the arrester.

Chemical Classifications
In the National Electric Code (see Table 1), chemicals are grouped according to their burning and explosion characteristics. The classifications
consider the MESG-Maximum Experimental Safe Gap (see Glossary of Terms for definition), maximum explosion pressure, and minimum ignition
temperature of the specific gas or vapor.

The categories recognized are Group A, B, C, and D. Group D atmospheres represent the least volatile flammable atmospheres, and the chemical
are represented as progressively more volatile through Groups C, B and A respectively. The stable detonation velocities and quenching diameters
of some of the common chemicals identified as representing Groups A, B, C and D are shown in the following table :

Flame Arrester Model Code

How to order

Example

Means a 8" model SFG with 304 stainless steel body, 316L stainless steel flame element,
ASME Class 150 RF flange drilling and no other option.