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Personal Data Policy
Liability
© 2022 Gas Service Consulting
All rights reserved
Services for Gas Pipeline Transportation Systems
Drying of Main Gas Pipelines Using Dry Compressed Air
Main gas pipelines, compressor stations, and gas distribution stations are integral components of the unified system of facilities required for natural gas supply. Gas humidity is a key indicator of its quality, ensuring gas transportation without the release of aqueous phase and gas hydrates. High-quality drying of the internal cavity of pipelines, as well as technological equipment and systems at compressor and gas distribution stations, is a critical task for gas industry enterprises.
The drying process of the inner cavity of the main gas pipelines involves various stages to remove residual liquids after hydraulic testing, followed by filling the cavity with dry compressed air.
Drying compressor and gas distribution stations using pistons is impractical due to the complex pipeline configuration in these systems. In such cases, water from the inner cavity of the pipelines is displaced by purging with air from a compressor with a pressure of 10-20 bar. The air velocity during purging can reach 15-20 m/s, effectively removing up to 20% of residual moisture at this stage. Subsequently, the system is purged with pre-prepared dry air with a dew point of -20°C to -50°C.
Gas Service Consulting LLC ensures optimal duration and quality of the drying process of technological system cavities through meticulous organization, the utilization of modern high-tech equipment and mechanisms, and highly qualified personnel on-site.
Inerting of the inner surface of natural gas pipelines and gas compressor stations
Creating an inert environment within the inner cavity of gas pipelines and technological systems, also known as nitriding (inertization), is a crucial technological step in preparing the system for the introduction of natural gas. During this phase, atmospheric air is replaced in the internal cavity of the system with an inert gas—nitrogen. This operation is essential to prevent the formation of explosive gas-air mixtures when filling a gas pipeline with natural gas or during system preservation. When conducting work to create an inert environment (nitrogen filling), Gas Service Consulting LLC adheres to STO Gazprom 2-3.5-354-2009, which regulates the execution procedure and quality criteria for work acceptance.
In nitriding projects (inert environment creation), Gas Service Consulting LLC employs modern and reliable equipment. Pre-purged sections of the gas pipeline are filled with dry nitrogen with a concentration of at least 98%, with a dew point temperature of -0°C (-30°C for sections of the linear part of the main gas pipelines laid in permafrost soils).
Nitrogen production in the field is carried out using two technologies:
- Cryogenic liquid nitrogen gasification (concentration 99.95% and dew point temperature not higher than -60°C): The production of gaseous nitrogen by this method is achieved using Mobile Nitrogen Gasifiers (MNG) consisting of a cryogenic tank and heat exchange equipment for changing nitrogen from liquid to gas. The equipment can be installed on a semi-trailer platform for delivery to remote locations. The cryogenic liquid nitrogen tank has a capacity of 15 tons (about 12,000 nm3), with an evaporator capable of gasifying liquid nitrogen at a rate of up to 2000 nm3/hour. The MNG operates at a maximum pressure of up to 23 bar. This method is economically viable when liquid nitrogen producers are within a distance of 1000 km from the work site. The MNG is quickly ready for operation, with nitrogen production commencing within 20-30 minutes of arrival at the site. The nitrogen injection line uses quick-release threaded connections and does not require electricity or diesel fuel provision.
- Production of nitrogen gas from the air by short-cycle adsorption: Gas Service Consulting LLC employs this technology for projects in remote areas or those requiring substantial amounts of gaseous nitrogen (over 60,000 nm3). This method ensures the production of nitrogen with 98% purity from the air, with a maximum operating pressure of 8-10 bar and a dew point temperature not exceeding -20°C. The nitrogen production plant comprises a compressed air compressor, a desiccant, and a modular adsorption unit. The nitrogen injection line uses quick-release threaded connections, and the unit includes a built-in system for controlling humidity (dew point temperature) and nitrogen concentration.