Dry and Liquid Flashback Arresters Analyzed in Brief

Compressed gas cylinders filled with fuel gases like acetylene as well as fuel propellants like oxygen are used in various industrial facilities. These gases are prone to flashbacks and backfire, which mainly occur due to human errors such as wrongly set pressures or faulty torches. Generally, the flame in fuel gas torches travels in one direction, but due to errors or abnormalities, it may travel back to the source causing a backfire. This backfire may lead to flashbacks when a gas mixture being transferred through any of hoses, pipes, or cylinders comes in contact with it. In case of a flashback, the flame races through the torch to one of the hoses used for supply. This may lead to dangerous consequences such as burning of the hoses, compressed gas cylinder explosion, and so on. Flame arresters are the devices that help gas users curb any such incidents of flashbacks and backfire.

Flashback arresters (FBA) feature dry or wet barriers that contain the fire and avoid accidents. Based on these barriers, the devices are distinguished as liquid flashback arrestors and dry flashback arrestors. This post introduces you to these types and their significance and ends by introducing you to a reliable flashback arrestor for oxygen and acetylene.

What Are Dry Flashback Arrester?

These flashback arresters use various types of safety elements to curb the flashback. Ceramic cartridges and sintered materials are a few common safety materials used for the purpose. The sintered materials are usually sand, bronze wool, and so on, which are porous. Dry flashback arresters are used in various cutting and welding applications.

What Are Liquid Flashback Arresters?

Also referred to as wet or hydraulic flashback arresters, these devices utilize non-absorbing as well as non-flammable substances like ethylene glycol to arrest flames. The gas is converted to bubbles, which is then made to pass through a liquid. These arresters are usually bigger than dry flashback arresters, and are preferred in fixed installations. Today, you can see many types of hydraulic flashback arresters in the market. Rexarc is one of the leading manufacturers of the same. The next section introduces you to one of the popular wet flashback arresters from the brand.

Get Introduced to Rexarc’s Liquid Flashback Arrester

The following are a few major components of liquid flashback arrestors:

• Inlet Pipe with a Check Valve
• Flow Diverter
• Outlet Pipe
• Relief Valve
• Liquid FBA Fluid

Here is how a gas passes through the flashback arrester:

• When a backfire or a flashback occurs, the gas enters into the device through the inlet pipe which features a check valve. The gas entering the device may have pressures ranging between 5 and 200 psi depending on the application. After settling, this gas pressure may reduce to 10 to 15 psi and it passes through the check valve.
• The gas next passes through liquid FBA that creates a double barrier between the high-pressure gases contained in the cylinder and down line users.
• The high temperature flame is curbed by the liquid, while the check valve prevents it from pushing upstream. By doing so, it prevents the flame from traveling to cylinders.
• One of the interesting features of this situation is that the relief valve cannot open fast to relieve the pressure. However, it is designed to prevent over-pressuring during regular operating conditions. It also serves as a vent for maintenance.
• The gas is reversed to the application through the outlet pipe.

Rexarc’s hydraulic flashback arrestors have been widely used in facilities using acetylene and compressed oxygen cylinders and torches. They help prevent the penetration of the gas into upstream equipment such as gas cylinders, hoses, and regulators. You can get in touch with the team at Rexarc for more information on its liquid flashback arresters and analyzing the possibilities of using them in your facility. The experts will work with you to understand the type of gas used in your facility, the setup of your facility, the material of the equipment, and so on.