Vapor Phase Pipe
The vapor phase pipe is a part of the loading arm designed to balance the air pressure inside storage tanks and transportation equipment. Its core function is to prevent medium leakage or equipment damage caused by pressure differences. In emergency situations, such as pipeline rupture or valve failure, the vapor phase pipe can act as a safety pressure - relief channel to release excess pressure.
For volatile media like LPG and liquid ammonia, the vapor phase pipe can reduce the evaporation loss of the medium during the loading and unloading process. This not only cuts down on environmental pollution but also lowers safety risks. Moreover, by maintaining a stable pressure environment, it helps to ensure the smooth progress of the entire loading and unloading operation. It can also assist in reducing the generation of air pockets in the system, which may otherwise disrupt the normal flow of the medium. In some cases, it can be connected to gas recovery systems, enabling the collection and reuse of volatile gases, which is in line with the concept of environmental protection and cost - effectiveness.
Liquid Phase Pipe
The liquid phase pipe is the part of the loading arm used for transporting liquid media. Its core function is to achieve the transfer of liquid media from storage tanks to transportation equipment (such as tank trucks, oil tankers) or in the reverse direction. The liquid phase pipe is directly connected to the liquid phase interfaces of the storage tank and the transportation equipment, ensuring the smooth flow of the liquid medium during the loading and unloading process.
The design needs to take into account the physical properties of the medium, such as viscosity and density. For example, for a medium with high viscosity, if the pipe diameter is too small, it may lead to slow flow and even blockage; while for a medium with low density, too fast a flow rate may cause problems. This is to prevent static accumulation or pipeline vibration caused by excessively fast flow velocity. Static accumulation may cause sparks and pose a danger when dealing with flammable media, and pipeline vibration may damage the pipeline connection and affect the service life. The end of the liquid phase pipe is usually equipped with a dropper or a special joint. This ensures that there is no residue of liquid after the loading and unloading is completed, reducing material loss and environmental pollution risks. Additionally, some advanced liquid phase pipe designs may incorporate flow - control valves or flow - measuring devices, which help to accurately control the amount of liquid transferred and monitor the loading and unloading process in real - time.
In general, the vapor phase and liquid phase pipes are complementary to each other. During the loading and unloading process, the liquid phase pipe and the vapor phase pipe work in coordination. By balancing the pressure, they avoid over - pressure or negative pressure in the pipeline, ensuring the safety of the operation. For example, when liquid is pumped into a transportation vehicle through the liquid phase pipe, the air in the vehicle needs to be discharged through the vapor phase pipe; otherwise, the pressure inside the vehicle will increase, which may cause leakage. Conversely, when unloading liquid from the vehicle to the storage tank, the vapor phase pipe can supplement the gas to balance the pressure reduction in the tank, preventing the tank from being deformed due to negative pressure. Their coordinated operation is the key to ensuring the efficient, safe, and environmentally friendly loading and unloading of liquid media in gas stations and oil depots.
