Pipeline Accessories
Industrial pipeline fittings: Types, Functions appeared thanks to the activities of the outstanding.Pipe fittings: Types, Functions It was he who in 1863 proposed to transport oil through pipes. But the first Russian pipeline appeared only 15 years later, in 1878. Since that year, and for almost 150 years now, pipeline valves have been ensuring the uninterrupted delivery of goods and the technological needs of production. Historians found the first mention of pipes in ancient records dating to the 5th millennium BC.
Types of fittings
Of course, since the appearance of the first tap, "a lot of water" has flowed under the bridge. Now the range of supply of pipeline fittings has become much more diverse. Manufacturers produce products based on:
• their function;
• areas of use;
• design features presented by buyers;
• operating principle and control method;
• installation method;
• and type of seal.
All over the world and in other regions of the world enterprises can order equipment based on their technological needs. The presence of transport companies (for example, ETK) simplifies delivery to the regions. Shopping malls can arrange delivery even for bulk orders.
Functions
Pipe fittings perform different tasks, and their design and other features depend on this.
1. Shut-off - de-energizes the substance's movement in the pipe.
2. Regulating - decreases pressure in the system by increasing the hydraulic resistance.
3. Protective - prevents a negative impact on the pipeline or pressure equipment. It does not allow the reverse movement of the medium or the excess of the specified flow rate.
4. Safety - protects the pipeline system and devices from increasing pressure.
5. Steam trap - removes the resulting condensate, which can lead to a water hammer or a decrease in system power.
Also on sale are devices that combine several functions at once. For example, shut-off and control, which perform the functions of complete blocking of the flow and adjustment of system parameters.
Scope of use
Pipeline fittings ensure the efficiency of various sectors of the national economy:
• oil production and oil refining;
• gas industry;
• civil utility networks;
• airlines for various purposes;
• emergency and fire systems;
• laboratories;
• water transport;
• energy facilities.
Each industry has its own requirements for safety and reliability. It is one thing to buy a valve for a sewage system, and quite another to buy a pipeline for a nuclear power plant. The requirements for acceptance and quality of such a valve are completely different.
As a result, pipeline fittings can be:
• general industrial - standard (GOST) requirements for production;
• special purpose – characteristic industry features, operating conditions, and reliability are taken into account;
• sanitary - for drinking water systems and other general business needs;
• energy - for energy facilities;
• cryogenic – for work with especially cold environments (below -1530С);
• laboratory - for research.
Manufacturers produce a specific type of device. For example, taps for water supply, sewerage, and heating are produced by one plant, and wedge gate valves and butterfly valves for large-diameter pipes are produced by another (LZTA Marshal, LAZ).
Hull design
Since the pipeline is a complex, branched system, for its normal operation, the pipes must be located as compactly as possible. When laying the highway, turns and bends are used to do this. But if in an apartment it is very easy to “wrap” the heating pipe, then it is not always possible to do this on gas and oil pipelines.
For this purpose devices are manufactured in:
• through passage;
• corner;
• as well as in multi-way design.
If the connecting pipes of the device lie on the same axis or their axes are parallel to each other, this is a thorough fitting. The angular position is characterized by the location of the inlet and outlet at an angle of 450. But multi-way valves have more than two nozzles and the medium current in which is regulated alternately.
type of drive
Pipelines are designed with a passage diameter from 50 to 2000 mm—accordingly, the size of the shutter and its mass change. For example, it is possible to close the passage of valve 30s41nzh ru16 with a diameter of 50 mm with the effort of one worker. But moving the shutter 30s941nzh du1200 mm with your hands is unlikely to succeed.
Therefore the valve is supplied with the following:
• manual;
• mechanical;
• electric;
• electromagnetic;
• hydraulic;
• or pneumatic drive.
Manual drive implies the presence of a steering wheel, with which the working body is lowered into the pipe or rotated around its axis. The mechanical drive device also provides for a steering wheel in the design. But there is also a gearbox, which reduces the required effort of the operator to move the shutter.
Electric, pneumatic, hydro, and also electromagnetic drives are mounted on large-diameter devices. In them, the movement of the shutter occurs from the control medium (current, air, water). Valves with these types of actuators can be included in the dispatcher interlocking system and controlled from a single remote control.
Pipe connection
For installation in the main pipe fittings are completed with the:
• flanges;
• clutch;
• fitting.
In addition, steel wedge gate valves and cranes can have a welded connection type. The edges of the branch pipes have metal cutting for welding. For the operation of firefighters and water supply systems, trunnion fittings are provided. But for butterfly valves, a wafer connection is used (mounting on pipe flanges
Reinforcement types
This classifier determines the design of the main working body - the shutter. According to GOST24856-2014:
• gate valve - the gate moves perpendicular to the axis of movement of the substance;
• valve - the shutter is installed arbitrarily to the medium flow and rotates around its own axis;
• valve - the plane of operation of the shutter is parallel to the flow of the substance in the pipe;
• butterfly valve - the working body (disk) moves around its own axis.
The design of the shut-off body determines the design features of the fittings, the types of seals, and the method of installation on the pipeline.
materials
For each node of pipeline fittings, materials are used that contribute to the maximum increase in the operational characteristics of the device.
Body parts are made of such metals as:
• cast iron and carbon steel (gate valves, cocks, valves, gates);
• brass (taps of small diameter);
• alloy steel (for severe operating conditions);
• aluminum;
• titanium.
Patronite (PON) or thermally expanded graphite (TEG) are used for seals of stuffing boxes of gate valves. The stuffing is supplied as a cord. For gate valves operated in severe conditions, PON or TRG is additionally reinforced with wire and impregnated with specialized compounds.
Moving parts of drives (spindle, rod, nuts, balls), which are subject to friction, are made of steels with high anti-friction properties. These are brass and stainless steel.
For the sealing surfaces of the gates, high-alloy steel grades are used. High demands are placed on shut-off devices for wear resistance, durability, and stability in operation when exposed to pressure and elevated ambient temperatures. Therefore, the alloy for seals has a high content of chromium, nickel, and titanium, as well as impurities of silicon and copper.
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