Dry gas seals (phớt khí khô) are non-contact seals that use clean gas to create a sealing membrane between the two seal faces. This solution is widely used for centrifugal compressors, pipeline compressors, and turbines in the oil and gas, and petrochemical industries, with the advantages of low leakage, low friction, and high reliability.
The rotating seal face is machined with very small spiral grooves. When the shaft rotates, the grooves introduce gas into the gap and create a lifting force that pushes the two seal faces apart, with a gap of only a few micrometers. Since there is no contact during operation, the seal is almost wear-free. When the machine stops, the spring pushes the two faces together to maintain sealing.
Single configuration for clean gas, low pressure. Tandem configuration includes primary and secondary seals, which is the most popular choice for hydrocarbon gases. Double configuration uses barrier gas (usually nitrogen) when process gas is not allowed to leak out. Separation seal (separation seal) in the form of a carbon ring protects the bearing from leaking gas and lubricating oil.
The gas panel includes a filter, pressure regulator, flow meter, and differential pressure sensor to supply clean, dry gas to the seal and provide early warning of any abnormalities. When the gas is easily condensed, heat tracing is required. The design often references standards such as API 692 and API 617.
Natural gas compressors, synthetic gas compressors, hydrogen compressors, CO2 compressors, blast furnace gas compressors, and compressor stations on gas pipelines.
The supply gas must be clean, dry, and have a higher pressure than the seal chamber. It is necessary to monitor the leakage flow and pressure difference, avoid liquid entering the seal when starting and stopping the machine. Regular maintenance according to the manufacturer's recommendations will extend the life of the seal.
SNS-VN supports consulting, selection, and supply of dry gas seals and support systems for compressors. Please contact us for a quote based on your machine specifications.