SPECIAL PROCEDURES SPECIAL PROCEDURES
After decades of work on the construction of main pipelines as well as the construction and maintenance of process plants company has developed the ability to perform the most complex mechanical works without the need to interrupt the supply through pipelines or with minimal stoppage of the process all while complying with strict health and safety rules and respecting the rules of environmental protection.
Meeting the conditions
In order to meet the required conditions set by the owners of critical infrastructure, whether they are operators of transport systems or owners of process plants, we have mastered various special procedures that we use when we carrying out work for own needs or as a service that we provide to other partners on the market.
Hot-tapping
the procedure of assembling and welding connections of usually smaller diameter to the existing pipeline without the need to stop the flow through the existing pipe. The most common application is in process plants (refineries, pharmaceutical plants, paper mills, offshore plants) where stopping the process is undesirable and/or economically unjustified. We currently have two drilling machines with which we can make connections form ½“ to 24“.
Cold cutting pipes process
a procedure for cutting pipelines without sparking, the mentioned procedure is suitable for carrying out work in process plants or on segments of transport system where a short-term stoppage of the flow is justified but it is difficult or economically unjustified to bring that segment of the pipeline to a state without an explosive atmosphere in order to cut it off with standard electric tools or gas cutters. The most common application is oil pipelines (whether it is a transportation pipeline or a pipe distribution at an oil terminal) and refineries.
During the construction of main pipelines as a confirmation of the correctness of the installation it is necessary to conduct a pressure test and it is also necessary to clean and calibrate the pipeline in order to prove that during construction there were no deformations on pipeline that could adversely affect the lifetime of the main pipeline. The above services, except for our needs, we also offer to the other partners on the market.
In addition to our needs, we also offer the above services to other partners on the market.
Pressure test of main pipelines
most often we are talking about pressure test that is conducted with cold water as a test medium (hydrotest) and in accordance with technical instruction according to DVGW G469 B2 which is carried out on buried pipelines for duration of 24 hours. When we talk about pressure test of main pipelines by which we prove the strength of the installation we are most often talking about the volumes of the test medium from several hundred to several thousand cubic meters and the length of the installation from several hundred meters to ten kilometres depending on the diameter of pipeline and test pressures of 75-150 bar. In order to successfully organize and carry out the mentioned test we have several pumps that need to pump the test medium into the pipeline, the most common sources being streams and rivers located near the constructed installation and high-pressure piston pump up to 150 bar.
Cleaning and calibration of pipelines
during the construction of main pipelines cold-bent pipe bends with radii greater than 32D are produced on the construction site and after backfilling and pressure test it is necessary to carry out the calibration of the pipelines in order to confirm the correctness of the installations, i.e. that no illegal deformations have occurred. Cleaning and calibration we conduct with our own produced compressed air driven pig’s using air compressors.
Pipeline drying
after the pressure test cleaning and calibration during which water (test medium) is ejected from the pipeline the pipeline must be dried before gas is released in. Drying is carried out with help of unit for drying and air preparation and after it has been established that dew point temperature of the air inside pipeline is within permitted limits (below -15 °C or lower) the pipeline can be inerted with nitrogen and consequently gassed or immersed in a liquid medium intended for transport, we also offer the specified service to other partners on the market in addition to our projects.
Protection of the excavated pits
when conducting work on the lying of underground installations sometimes they are laid in relatively deep trenches and it is necessary to secure them from collapse in order to enable safe work for the employees. We have steel piles and rammers with which we conduct the beforementioned securing of the excavation.
Pipe-bending
during the construction of main pipelines it is necessary to produce pipe bends on the construction site according to longitudinal profile from the project. The pipe bends are bent from the pipes using hydraulic bending machines with or without internal mandrel. As a company we own 3 bending machines for cold bending with which we can bend pipes with diameters form 3“ to 32“ except for the needs of our projects we offer this service to other partners on the market.
In addition to special procedures related to the execution of mechanical works we are also able to offer the market special civil works in form of horizontal drilling services and protection of excavated pits.
Horizontal drilling
a procedure by which part of the pipeline is built without the need for digging (roads, highways, railways, rivers, etc.) if it is impossible to close traffic and conduct classic digging due to the traffic load. We can drill and insert protective pipe up to Ø1200 mm in diameter we also offer this service to other partners on the market.
Protection of the excavated pits
when conducting work on the lying of underground installations sometimes they are laid in relatively deep trenches and it is necessary to secure them from collapse in order to enable safe work for the employees. We have steel piles and rammers with which we conduct the beforementioned securing of the excavation.
MONTER STROJARSKE MONTAŽE
