Where is the most appropriate location to install the pressure sensing point for low low fuel gas pressure in a heating furnace?
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As the title suggests, experts: for a low fuel gas pressure monitoring point, should it be located before the fuel gas shut-off valve or after the flame arrester? How are those you’ve installed designed?
It must be before the shut-off valve; it’s certainly not after the flame arrester. If it’s after the shut-off valve, it becomes very difficult to restore normal operation in case of a chain reaction. Clogging of the flame arrester is a common problem, so that’s not an acceptable option
It can be installed in front of the control valve, or on the fuel gas liquid separation tank or buffer tank. It should not be behind the control valve.
It should be placed in front of the shut-off valve and the control valve
We installed it right after the control valve, so the interlock simply cannot be activated.
It is generally installed in front of the emergency shut-off valve; the pressure behind the control valve is usually very low. If it is installed behind the control valve, the self-protection valve will not function
Both of the furnaces in our unit are designed to be located after the flame arrestor
It should be after the control valve and before the shut-off valve. Reason: First, taking a pressure measurement point after the control valve allows for monitoring of the pressure of the fuel gas entering the furnace, which is also the purpose of setting up such a pressure measurement point ； Secondly, it ensures a rapid recovery after interlock shutdown in front of the shut-off valve, whereas it is difficult to recover after interlock shutdown behind the shut-off valve.
The gas flow path into the furnace consists of an interlocked cut-off valve, a control valve, a flame arrester, and then three pressure tapping points.
A fire arrestor blockage usually also occurs instantly. If it is installed behind the flame arrester, the pressure difference across the flame arrester can also be estimated based on the pressure behind the flame arrester and the pressure in the fuel gas network. It is possible to determine when to clean the flame arrester. Once a chain reaction occurs, why is it difficult to reverse? If the pipeline network pressure is normal and the interlock is triggered only due to an issue with the instrumentation, one simply needs to bypass the interlock and then open the shut-off valve.