How to define the pipeline insulation scope for LNG vaporization stations
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In previous designs by design institutes, insulation was typically applied to the process of unloading liquid into the tank as well as to the pipelines that carried liquid from the tank to the vaporizer. However, no relevant standards or papers were found to explain why this was done; only industry practices were available, which state that liquid-phase pipelines must be given special low-temperature insulation, while gas-phase pipelines generally do not require such insulation. Operators have asked why insulation is still used for the pipelines carrying LNG to the vaporizer, since the purpose of those pipelines is indeed to vaporize the liquid I wonder if it’s just for safety and to prevent frost damage, as well as because LNG pipelines can freeze; in summer, water accumulation is likely to occur in the process area, and in winter freezing can happen, posing risks to the entry and exit of operators? ? The liquid outlet from the LNG storage tank leads to a degasifier that lacks insulation – does this have any impact on the safety of the process pipelines?
Insulating the LNG liquid-phase pipelines is intended to prevent the temperature inside the pipes from rising too rapidly, which could lead to rapid gasification and subsequent pipe expansion. As a result, the liquid-phase safety valve will trip frequently. One is danger, and the other is waste. Add a insulation layer. Ensure that LNG is vaporized in an air-temperature vaporizer as much as possible, in order to reduce operating costs and the risk of hazards.
Thank you for clarifying this; now I can convince those property owners who want to save trouble
I also had doubts before, thinking it was purely for safety reasons; now I realize I was oversimplifying things – what was said on the second floor makes sense
There are only two requirements for insulating LNG pipelines: 1. The main purpose is to reduce the amount of heat absorbed by LNG during transport through the pipeline, which would otherwise cause the LNG to vaporize and result in a mixture of gas and liquid within the pipeline, thereby reducing its flow capacity； 2. The next priority is to prevent frostbite among operators.
The first floor has already been explained very professionally; I’ll add just a few things. Typically, LNG receiving station projects are located by the sea; therefore, without insulation, condensation and freezing occur throughout the year. Coupled with the high halogen content in the sea air, this exacerbates the corrosion of stainless steel structures. Generally, the principle for considering personnel protection (PP) is that pipes or equipment located within 2 meters of pedestrian pathways or operation interfaces require personnel protection measures.