How to select the control valves for regulating the pressure of natural gas entering the atmospheric-pressure furnace and the temperature of crude oil?
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Our facility’s atmospheric pressure furnace originally had a light oil system; now we want to use natural gas as fuel for this furnace. For safety reasons, we are unsure how to select and adjust the control valves in order to automatically regulate the pressure of the natural gas entering the furnace as well as the temperature of the oil output. We would appreciate it if experts could provide some suggestions. Thank you
For regulating the natural gas pressure entering the furnace, use one control valve and one pressure transmitter; together these two components can be used for regulation. It’s best to have a buffer tank, install the pressure transmitter on the tank, and place the control valve in front of the tank; this should yield the best results. Oil outlet temperature: the ignition system is controlled by temperature; when the temperature rises, the ignition system shuts off. If you want to control these two together, it’s not easy; it’s better to keep them separate! ....I think it would be good to reduce the amount of maintenance needed. .....In fact, a self-acting control valve can also be installed to regulate the natural gas pressure. So, what pressure do you need for the natural gas? It’s uncertain what the effect of adjustment will be… If the effect is not good, the amount of maintenance required may increase. This is mainly due to leakage issues with the self-acting control valve. If natural gas is not used later on, once the pressure reaches the alarm level, the self-acting control valve will close, but it might not do so completely. This is a common problem with self-acting systems. Of course, if you choose a suitable self-acting valve based on your pressure regulation range and inlet/outlet pressures, it may also yield good results. Think about it more... What I said is just my personal opinion. I’m not very familiar with the selection of self-acting types and their pressure regulation performance.
I also want to ask if there are any special requirements for control valves used with natural gas, and how should they be selected? Thank you
The flow rate of natural gas is generally not high; for precise control, electric regulation can be used, as well as pneumatic regulation. The sealing and explosion-proof ratings must be sufficient, along with an adequate level of control precision. There’s nothing else that needs to be considered. Just my personal opinion. Actually, there are many different options for such a system solution; installing a shut-off valve along with a pressure reducing valve is also a great choice!
Natural gas to atmospheric pressure furnace: manual valve--ball valve--solenoid valve--filter--overflow valve--reducing valve--overflow valve--vent valve--solenoid valve--manual valve. Of course, a bypass is also added to this pipeline to prevent damage to the components in the main pipeline. Specifically, I can provide pipeline design.