The installation of alloy steel pipelines basically includes the same technological operations as the installation of carbon steel pipelines, but has some features. As a rule, pipelines are made from alloyed steels, which are subject to increased requirements in terms of density, strength, and corrosion resistance. Therefore, technological operations for the assembly, welding and installation of alloyed pipelines are performed by highly qualified workers.
Elements and assemblies of pipelines from alloyed pipes are manufactured centrally in pipe-producing shops and workshops. Finished assemblies, elements, parts and fittings are transported laid on wooden decks separately from carbon pipes. Upon acceptance for installation, they are inspected, carefully checked for compliance with the markings and certificates of the project and specifications. All parts of pipelines made of alloy steel are subject to inspection and testing.
At the assembly site, the pre-assembly of elements and assemblies into blocks is performed on special racks. When using steel ropes for slinging alloyed pipes and parts during unloading and lifting, wooden linings or tarpaulin are placed at the points of contact between the cable and pipes to protect the pipes from mechanical damage.
Alloy steel pipelines are laid on conventional supports, hangers and supporting structures. However, in order to avoid the formation of corrosion centers, the pipes are isolated from direct contact with carbon steel parts and structures. To do this, the supports are painted with oil paint or plates made of sheet asbestos and alloy steels are installed between the supports and pipelines. Pipes made of heat-resistant high-alloy steels are insulated from supports with asbestos sheet gaskets.
Welding of tie bars, brackets and lugs for assembling joints is prohibited for alloyed pipes.
Connections of pipelines made of alloy steels can be welded and flanged. Flanged pipe connections made of alloyed, especially of stainless steel, it is recommended to produce loose flanges with flanged branch pipes or welded rings.
The installation of process pipelines with an internal coating does not fundamentally differ from the installation of uncoated pipelines, but has some specific features.
The installation of lined pipelines is made from parts prefabricated at the factories, including straight sections. Before starting the installation, pipes and parts are, if possible, enlarged into nodes and blocks, straight sections - into sections. Lined pipes, fittings and fittings, as a rule, are connected to each other on steel flanges. These pipelines must be short with the minimum amount elbows and flanges and not have sharp turns. Lined pipelines may only be installed at positive temperatures. Pipes, parts and fittings transported or stored at sub-zero temperatures must be kept in a warm room (not lower than +10 ° C) for 24 hours before installation. h.
Sections of pipelines with detachable connections must be located away from the passages and protected with removable casings. Pipe connections must be accessible for inspection and repair.
At underground laying pipes lined pipelines transporting aggressive environments, should be located at the bottom, away from hot pipes and other sources of heat. Channelless laying of lined pipelines is not recommended.
Lined pipelines are laid with a slope, the value of which depends on the properties of the transported medium. Minimum allowable slopes: for liquids - 0.001-0.002; for gases (against the course) -0.003; for gases (along the way) -0.0015.
When laying pipelines from lined pipes, “bags” (places of accumulation of product or air) should be avoided. At the lower and upper points of the lined pipelines, it is necessary to provide for the installation of lined tees to ensure drainage and air removal. To protect the lined pipeline from static electricity, it is necessary to connect adjacent sections of the pipeline with a conductor to create a continuous electrical circuit. In several places, it is recommended to connect the pipeline with a conductor to the common ground loop of the workshop or installation.
The deformations of the lined pipelines resulting from temperature changes are compensated for in the usual way.
The supports of lined pipelines practically do not differ from the supports of steel pipelines. However, the design does not provide for welding of any elements to the lined pipes.
Lined pipelines must be painted and have an arrow indicating the direction of movement of the medium. Colors of paints are chosen according to the project.
In the process of assembling a pipeline from lined pipes, shocks and other mechanical and thermal influences that can violate the integrity of the lining layer of pipes and fittings are not allowed. Tighten flange connections cast iron, fittings and fittings should be handled very carefully to avoid breakage.
Damaged lined pipes and fittings, in which the metal shell is destroyed or the lining layer is broken, are not repaired (except for rubberized ones), they are replaced with new ones.
When installing lined pipelines, it is strictly forbidden to cut and cut holes using a fire method, as well as to weld fittings, bosses and plugs into the pipeline.
Branches of pipelines are performed only by installing lined tees or crosses.
Closing sections during installation are made in place, that is, by carefully measuring the actual dimensions. The fitting of the closing sections is carried out by cutting off the overlaps and installing free flanges on the threaded ring with the flanging of the lining layer or by making such a section from alloy steel.
1. What is the peculiarity of the installation of pipelines made of alloy steels?
2. How are pipe surfaces protected from damage during transportation and installation?
3. What is the peculiarity of the installation of pipelines with internal coating?
Stainless steel welding is widely used in various industries. The properties of steel, such as strength, reliability, durability, meet the requirements for this equipment. In addition, steel does not interact with most chemical substances, including aggressive ones.
Stainless steel pipelines are used in enterprises processing oil products and gas, in the chemical and food industries, as well as in potentially hazardous industries. They carry out the transfer of industrial raw materials and finished products. In addition, process pipelines supply fuel, water, steam and various chemical compounds necessary for production processes.
Steel pipes able to withstand pressure and vacuum, high and low temperatures of the medium being transferred. Pipelines of various purposes carry out the transport of the product, both over long distances and within the enterprise. They are divided into three hazard classes. Class "A" is for toxic and hazardous substances. Class "B" includes combustible, explosive, flammable substances. Class "B" - these are non-hazardous and non-combustible environments.
Material requirements
For stainless pipelines, alloy steel is used, which has technological weldability, elongation at break and impact strength. Pipeline manufacturers carry out quality control incoming steel. If the pipes have seams, longitudinal or spiral, it is necessary to carry out their ultrasonic or radiographic inspection.
Installation Requirements
When installing steel technological pipelines, it is possible various ways their connections. For food and pharmaceutical industries, they create quick-folding structures. This is necessary to comply with hygiene standards, which provide regular flushing of pipes. In other industries, various mounting systems are used based on couplings and gaskets, threaded connections or welding. Welded joints considered the most reliable, they are used in the extraction and processing of oil, gas and in the chemical industry. Welds are subject to very stringent requirements. The personnel carrying out such work must have high qualifications, which they periodically confirm, and work experience.
At the time of welding, it is necessary to take into account a number of parameters under which it is permissible. These are the ambient air temperature, the condition of the pipes to be welded, their preliminary cleaning. Welded structures are launched in further work only after they have completely cooled down. A very important stage of work is the quality control of welds. They are tested in various ways. In addition to a systematic check of welding materials, pipeline elements, assembly accuracy, tests are also carried out at the end of work. Joint samples are cut and analyzed, ultrasonic, radiographic, X-ray, magnetic particle and other examinations are carried out, they are tested under hydraulic and pneumatic loads.
50,000-75,000 rubles per monthResponsibilities: - work on the pipeline; gas pipeline; - installation metal structures, technological pipelines and technical equipment... pipelines and industrial equipment; - waterproofing works; - piling and foundation works; - work...
Process pipeline installer
interviews (from 65 000 rub.) providing overalls, tools housing is provided in Moscow and at the facilities Responsibilities: installation pipelines... stainless steel, PVC, PP installation pipelines PVC and water treatment equipment preparation of pipes and fittings for welding, installation on the...
Process piping installer
Due to the increase in the number of objects, experienced installers are required technological pipelines. Registration in the staff for a permanent ... job (not a watch!). Responsibilities: - installation pipelines stainless steel, PVC, PP - installation water treatment equipment - pipe preparation...
Design engineer for the installation of technological equipment
Avan-Tek - Moscow 60,000-100,000 rubles per month
Responsibilities: Participation in the preparation of technical and commercial proposals in the direction of: " installation technological equipment". To produce ... metal structures technological platforms and fastening elements of technological equipment. Technical support project managers for workers...
Water treatment equipment installer
Group of companies Water.ru - Moscow 30,000-50,000 rubles per month
mechanical, physico-chemical water treatment. Understanding of water preparation and disinfection processes. Installation pipelines PVC, PP. Knowledge..., technological schemes. Work with the Customer. Requirements: Knowledge in the field of water treatment and water purification. Work experience from 3 years. Understanding processes...
Team for external engineering networks
SK ENERGOSTROY - Moscow 55 000 rub. per month
; Rain sewerage device; Construction of oil and gas industry facilities; Repair and installation equipment, technological... pipelines CHP; Reconstruction and construction of boiler rooms and boiler equipment. Design Heating network Water supply networks and...
Territorial sales manager
"Fössen IM I" - Moscow RUB 57,400-75,000 per month
technological pipelines. We are a small, young, rapidly and successfully developing company. In less than a year, we managed to take a very... "Vössen" is the production and sale of pure gases and gas mixtures based on them, equipment for pure gases, design and installation...
Electric gas welder-argonist
BVT - Moscow 72 000 rub. per month
Job Responsibilities: Welding technological pipelines from stainless steel with and without blowing, with and without additives ... Manual TIG welding Preparation of pipes and fittings for welding, installation on building construction Maintaining welding documentation, endoscopy...
Installer / fitter
Flame E1 - Moscow 50 000 rub. per month
Plamya E1 company announces recruitment of employees for the position of installer pipelines Responsibilities: Installation piping (internal) for..., technological installations of gas industry facilities, warehouses, hangars, underground garages and parking lots, special purpose centers (business ...
Building Control Engineer
Intertek (Moody International) - Moscow
sequence and composition technological operations during the construction of the Facility; Takes part in the examination of work in accordance with ... pipes and rolled products for their manufacture, pressure vessels, metal structures, components for construction pipelines And...
