TM Pipeline Service Pipeline Pre-Commissioning Services and Air-Drying, Process Pipe Installations and LNG Tanks

Since March 2005 TM Pipeline Service has offered a revolutionary air-drying system, which is used for the drying of large diameter and long section pipelines, piping and production systems, and LNG tanks.

Several techniques can be applied when drying a pipeline, however super dry air has been found to be the most economical compared to vacuum drying or the use of methanol or nitrogen.

In addition, TM Pipeline Service offers a full package of pipeline pre-commissioning services, which includes the following:

• Pipeline pre-cleaning
• Water filling
• Hydrostatic testing
• Internal gauging
• Dewatering after hydrostatic testing
• Inline caliper surveying for detection of dents and ovality
  Final cleaning by using either wire brush pigs and/or foam pigs combined with high volume dry air-flow
• Air-drying of mainline and installed valve and scraper stations to low dew points
• Nitrogen purging and packing prior to commissioning
• Sale of foam pigs

Pipeline air-drying system

TM Pipeline Service is specialised in the drying of pipelines, mainly through the use of air-drying. We offer an unparalleled air-drying system, which is revolutionary compared to any other known drying technique. The high volume-low pressure drying technology, based on dry air blowing, is used to dry large diameter and long pipelines, process plants and LNG tanks.

The new drying units are able to dry out a pipeline much faster and with a significant reduction of fuel consumption and reduction of CO2 emissions, compared to traditional drying equipment. A drying spread, capable of producing up to 15,000m³ of dry air per hour, consists of only two 20ft containers.

Super dry air with a dew point of approximately -40°C or lower is injected into the pipeline. As the air passes through the section, it absorbs any moisture that has been left after the hydrostatic test.

Foam pigs with a large absorptive capacity are used to distribute the residual water left in the line onto the pipe wall, thus increasing the areas of contact between residual water and air.

Air-drying units for long pipelines

Due to the high volume of dry air produced by our drying units, it is now possible to dry out even longer sections of pipeline than when using traditional drying equipment. It has been proven several times that the drying of a 230km pipeline in one section can be easily performed when using TM Pipeline Service’s drying system. Our well-approved drying method has been applied worldwide in pipelines with diameters from 6in to 56in.

Technical details of the air-drying system are as follows:

• Volume: 15,000m³/h (9,000cfm) at sea level
• Dew point: -20°C to -45°C
• Discharge air: 100% oil-free
• Fuel consumption: 50l/hr – 80l/hr depending on discharge pressure
• Maximum discharge press: 0.8bar (1bar) at 15,000m³/hr
• Size: two 20ft standard containers
• Weight: 10,000kg per container
• Connection to pipeline: four 6in flex hoses
• Year of construction: 2005 / 2006
• Environmental: no environmental disposal

Pipeline air-drying system advantages

TM Pipeline Service’s air-drying system offers customers several advantages. For instance, the system provides better cleaning of the pipeline due to higher velocity, less crane movement and lower pressure in hoses and fittings (maximum 1bar), and less personnel are required to operate the equipment.

The system also offers environmental advantages, such as the use of 100% oil-free air injected into the pipeline or piping system, less exhaust emissions due to less fuel consumption, less transportation and fuel storage required on site. Additionally, fewer on-site oil changes and service are required, as a section can normally be dried within the service interval of the engines.

The system’s high volume capacity minimises the risk of a foam pig being stocked in the line, due to air is bypassing. The equipment is easy to handle and transport as it is built in standard containers, and also requires a smaller area to set up the equipment (only three 20ft containers).