Type of roof flame arrester
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A flame arrester is first installed on the top of the storage tank, followed directly by a breathing valve for venting air; there are no pipes afterward. So, should an explosion suppression device be chosen for suppressing deflagration or detonation? According to SH3413, a breathing valve is considered a pipe component with a reduced cross-sectional area; therefore, an explosion suppression device designed for deflagration cannot be used. On the other hand, a device designed for suppressing detonation has an L/D ratio that is too small, which also does not meet the requirements. I’m stuck and hope that experts can offer some advice
A flame arrester is a fire protection device used to prevent open flames outside the tank from spreading inside it; when the distance required to prevent detonation is not sufficient, a conventional flame arrester is sufficient. Since the outside is on fire, the flame arrester can only prevent fire from entering the tank through the breather valve; it cannot prevent fire from entering at other locations.
Based on your description, since there is a direct connection from behind the flame arrester to the breather valve, which leads to the atmosphere, with no other pipes present, this situation is better suited for the use of a blast-suppressing type flame arrester. Although there are concerns that the L/D ratio may affect performance, for safety reasons, blast-resistant flame arresters are better at preventing flame penetration, especially in environments where rapid combustion or explosion may occur. You can consider choosing explosion-proof products of appropriate types, verify whether their L/D ratio meets the relevant specifications, or seek technical support from the manufacturer to ensure the effectiveness and safety of the products. .
Boss, a breathing valve is a type of flow-limiting fitting – is it possible for it to accelerate the spread of flames and cause them to exceed the speed at which deflagration can occur? Is it reasonable to consider the case where a breather valve is not present? If a vent pipe is connected after the breather valve, but the L/D is still less than 50, should it be considered for preventing deflagration or for preventing detonation?
A vent valve is indeed a flow-limiting fitting that can cause changes in fluid velocity, and theoretically it is possible to accelerate the speed of flame propagation. If not installing a breathing valve is considered, then the design and safety analysis of the entire system need to be re-evaluated; in such cases, it may also be feasible to use an explosion-proof flame arrester, depending on the specific operating conditions and environment of the storage tank. However, returning to your question, even if a vent pipe is connected after the breather valve, if the L/D ratio remains less than 50, this generally does not meet the requirements for using an explosion-proof flame arrester, as it may not be possible to effectively prevent the penetration of rapid and high-energy flames. In such cases, it is recommended to use flame arresters designed to prevent deflagration; these are designed to handle high-speed, high-energy flames and are more suitable for environments where explosive mixtures may exist. Furthermore, it is advisable to consult the manufacturers of flame arrestors and vent valves to obtain specific technical support and product performance data, ensuring that the selection meets safety standards and the requirements of actual operating conditions. .
There should be quite a few on storage tanks. What are everyone’s thoughts on this?
Thank you. This kind of thing is probably quite common on jars, but it’s better to clarify
Why not consider a flame arrester at the upper pipe end behind the breather valve? Choose the explosion and combustion prevention type for greater safety and effectiveness.
It seems that more are installed at the front; a quick search online shows that the tops of the tanks are installed at the front
This post was last edited by weilongwu on 2024-8-30 09:49. The flame arrester can be adjusted to be located behind the breather valve and face directly toward the atmosphere, which complies with requirement 6.2.8 of SH/T3414; thus, there is no issue regarding the distance to potential ignition sources, and it can be used for preventing explosions and fires. Additionally, for your case, as long as it meets 6.2.10 Lu/D of SH/T 3414
If you’re too concerned about this, install a non-stable detonation arrester with bidirectional fire suppression functionality; it’s just that the price is high.