Who do you turn to when your plant operates in extremely cold ambient temperatures and you need to pump light hydrocarbons near their vapor pressures? One of the world’s largest international LNG projects turned to Sundyne for their pumping needs, due to the strength of our technology, our relationship with all of the major EPCs that serve the LNG industry, and our successful track record with LNG customers around the globe.
This LNG project presented two unique challenges for pumps – that most manufacturers were not willing (or not able) to embrace. The first challenge was that the packages had to be able to operate at ambient temperatures as low -52°C (-62°F). The second challenge was that the light hydrocarbons pumped (ethane, propane, butane and NGL) were close to their vapor pressures. This condition makes sealing demanding as it increases the risk of dry running of the mechanical seal faces. Mixed-phase process fluid can lead to excessive heat generation and wear of traditional liquid seals.
To address the extremely cold ambient temperature, Sundyne winterized the complete skids and selected equipment suitable for temperatures down to -52°C. The lube oil system was equipped with a heater and all lube oil piping lines were heat traced and insulated. The instrumentation for the lube oil pump, the oil filters and the API seal plan all needed to be housed in heated boxes.
The sealing challenge was solved with a dual unpressurized seal configuration with an intermediate labyrinth. Due to the risk of mixed-phase fluid, diamond-coated silicon carbide faces (which can operate in both liquid and gas phases) were chosen for the mechanical seal faces. The cartridge seal was engineered for the high speed (26,000 RPM) and high-pressure application (35 barg dynamic sealing pressure, 130 barg static sealing pressure).
Sundyne successfully tested the pumps at full speed and pressure on water and nitrogen to validate the mixed phase operation. This sealing solution virtually eliminates leakage, offers extended lifetime and guarantees a wear- and contact-free operation. Moreover, this was achieved with a minimal footprint, due to Sundyne’s compact high speed LMV pump design.
The ability to address unique pumping requirements played a big role in winning this business. But equally important was the fact that Sundyne was also able to provide overhead gas compressor packages and regeneration gas compressor packages required for the liquefaction process. The EPC in charge of this project has a successful track record working with Sundyne, and EPCs in other parts of the world have successfully delivered similar pump and compressor packages to support major LNG plants in the US-gulf coast, and in Australia.
