Flame arresters are at times mounted directly upstream of pressure / vacuum relief vents, or are connected to short runs of open vent outlet piping. These devices, known as “VENT-LINE / IN-LINE” flame arresters are designed with flanged or threaded mounting connections on both the inlet and outlet. It is possible for a flammable vapor / air mixture to ignite within the confined space of the short outlet pipe or within the vent body. Such an ignition is referred to as a confined deflagration. The flame speed is slow and pressures within the vent piping are relatively low. The Vent-Line / In-Line Flame Arrester is designed to stop this type of flame front. Note: these arresters have very specific limitations as to where they can be properly located within the system.
Vent-Line / In-Line Circular Plate Flame Arrester
The Protectoseal Series No. 4950 Vent-Line / In-Line Flame Arrester is designed to be installed in open vent pipes or bleed lines from storage or processing tanks. The arresters are used to prevent the propagation of an external flame through the vent opening and into the tank. They provide maximum air-flow consistent with operating efficiency and safety. Listed by Underwriters’ Laboratories (UL) in 1″ through 10″ sizes. Factory Mutual (FM) Approved in all sizes.
When properly mounted in a open vent pipe line, the Series 4950 Flame Arrester allows vapors to discharge into the atmosphere and allows air to be drawn into the pipe through the flame arrester grid assembly. If an external flame source is encountered, the device prohibits passage of the flame into the tank’s vapor space. They may be installed within specified distances from the end of an open vent pipe. The 1″ size is listed for installation at distances up to 50′ from the open end of the pipe. The 2″ size and larger are listed for installation up to 20′ from the open end of the pipe.
Vent-Line / In-Line Crimped Metal Flame Arrester
The Protectoseal Series No. 30000 Vent-Line / In-Line Crimped Metal Flame Arrester is designed to be installed in open vent pipes from storage or processing tanks. The arresters are used to prevent the propagation of an external flame source through the vent opening and into the tank.
The Series 30000 utilizes wound, crimped 316 Stainless Steel foil strips to form a heat transfer matrix of uniform triangular cells within the circular element. The unitized crimped metal element provides a straight thru flow path, low pressure drop and is less susceptible to clogging. The element is mounted between arrester housings that connect to the pipe flanges. The arrester elements are removable and interchangeable to facilitate inspection and maintenance. A clean element may be inserted during inspection to insure positive flame protection at all times.
When properly mounted in an open pipe line, the Series 30000 Flame Arrester allows vapors to discharge into the atmosphere and allows air to be drawn into the pipe through the flame arrester element assembly. These arresters may be mounted within 20′ of the end of the open vent pipe in either the vertical or horizontal position.
In-line Deflagration Flame Arresters
The Protectoseal Series Nos. 46000E & 46000E In-Line Deflagration Flame Arresters are designed to withstand low, medium and high pressure deflagrations (subsonic). These arresters are bi-directional and capable of stopping a flame approaching from either direction in a piping system and can be mounted vertically or horizontally in the pipeline. Suitable for varying distances from the unprotected side of the vent pipe, maximum distance (Lu/D=50), and within determined operating pressure, consult factory for specifics.