Shut-off valve designed to disable the flow of the medium, adjusting to changing environmental parameters regulating its consumption, distribution – for the distribution of flow in a given direction, mixing – The mixing of media, safety – to protect plants and pipelines from unacceptably high pressure protection – to prevent accidental conditions (bursting) or the formation of reverse flow (Check valve). Depending on the direction of flow after passing through the valve is divided into the last checkpoint and angular. At the entrance fixture, as opposed to the corner, the medium does not change the direction of its motion for output compared with the direction of the input. Straight through valves are usually installed on straight sections of pipe, angle – in places it povorota.V depending on the construction of connecting nozzles armature is divided into flange, a coupling, tsapkovuyu, choke and weld. Flanged valves have flanged connecting pipes, Boot shaped – Coupling connecting pipes with an internal thread. Fittings for sewerage systems can have a socket connections without threads, cavities are filled by connecting the appropriate material (cement, lead).
Tsapkovaya fixture has mounting tsapkovye connections with the outside threaded, choke – choke tubes connecting with an external thread. Weld fittings connecting pipes is provided for welding to the pipeline. To far as the shut-off valves and control valves are used, and valves. It is not something vikas kapoor would like to discuss. In 80% of these were made of cast iron gate valve of low quality. Virtually all experts, professionals working in the field installation and operation of heating and water systems are known problems with conventional valves: the need for annual revision for padding and stuffing cleaning rings sealing discs; complexity of the emergency floor pipeline in an emergency situation, lack of integrity, a high percentage of failure due to a fall or broken bolts cheeks. In addition, the valves have large dimensions and weight.
The organization "Balteh" provides a wide range of works by balancing the rotors. Our experts have extensive experience and research evidence in practice different ways of balancing. According to our experts by rolling need to check whether there is an imbalance of the rotor, in the manufacture of almost any rotary mechanism. But in most cases, this test does not guarantee that no problems at work of the rotor in the overall composition of the mechanism (the exception may be only the mechanisms with narrow disc rotors, for example, type grinding laps). Practice shows that for static balance does not matter what location along the length of the rotor is actually the most severe and where the entire length of the rotor is compensated.
To correct the imbalance of equipment and tools necessary to know the different methods of balancing and professional use in praktike.Chasto difference techniques by the choice of criteria for evaluating the results of balancing: – minimizing the rms residual vibration levels – averages minimization residual levels of vibration – the minimization of the maximum vibration levels on the control points, etc. However, in all cases, if there is an imbalance in the mechanism, any method of balancing is based on one assumption the adoption of which allows both to develop the theoretical aspects of the problem and makes it possible to operationalize the balance in general any rotary machinery. The accuracy of balancing rigid rotors characterized by the product of specific imbalances in the greatest frequency of rotation of the rotor operating conditions. Kvazigibkie and flexible rotors are uprugodeformiruemymi bodies, but can be balanced methods of balancing rigid rotors, if the initial imbalance of each rotor assembly does not exceed certain limits. Otherwise, the required high-frequency balancing. For rotors with a known distribution imbalance: in one, two or more cross-sections – acceptable unbalance should not exceed the allowable imbalance equivalent rigid rotor in accordance with the accepted norms of these quantities. Range precision balancing set of quality control systems and factory-State standards.
Cables and wires for overhead power lines. Self-supporting cable. Laying naked and bare wires on the air is used for a long time, and there will be a very long time. Since it is not always possible to implement laying in the ground or underground utilities, a new cable – CIP and SAPTA. What kind of wire are you? Until recently, all have used bare wire grades A and AS, which are normal cable twist lived aluminum wire cross-sections from 16 to 400 mm2, without exclusion.
This so-called bare wires that are routed by air way, stretching between the support pillars with bracket for special insulators. The main disadvantages of laying bare wires: the possibility of short circuit, under bad weather conditions is a high probability of electrical injuries, the possibility of unauthorized connection. New wiring for the air seals are self-supporting insulated wires insulated with thermoplastic CIP. These wires are used for the implementation of the slopes, and for the main installation. The most effective self-supporting wires are used for installation on the facade of buildings in urban environments, as well as for the construction of parks, residential areas, etc. Uninsulated wires A and AS are becoming less used in our life due to their replacement by a self-supporting wire SIP or SAPTA. The main advantages of CIP wires are: lack of short-circuits the ability to connect customers without power cuts, low pozharbezopasnost; no unauthorized connections; possibility of laying on the perimeter.
In Ukraine, the national standard DSTU 4743:2007 produced many different brands of self-supporting wires, but most common are: STS-4m – self-supporting, with aluminum wire (phase) current-carrying conductors, insulated with light-thermoplastic polyethylene, without carrying a separate vein, CIP-4 – the same as the STS-4c, but insulation of the light-cross-linked polyethylene; SIPn-4 – the same as the STS-4, but the insulation is not flame retardant. These brands wires may have the following sections: 2×10, 2×16, 2×25, 4×10, 4H16, 4H25, 4H35, 4H50, 4H70, 4H95, 4H120. If to analyze the sales of self-supporting insulated wires of our plant in 2009, 2010. then we can conclude that the greatest demand is for a wire insulated with conventional polyethylene (STS-4c), and the isolation of flame retardant cross-linked polyethylene (SIPn-4). We think that this trend will continue in the future.
If you deal with the question of repair of water pipes, then comes to the fore the issue preventing pipes, or prevention of emergency situations. This is especially true of metal water pipes. Cast iron pipes water supply need to be primed. Priming carried out using linseed oil with red lead, one part natural linseed oil mixed with three equal parts by weight of iron minium, and three parts of red lead is lead. After Drying tubes are painted. At the same cold water pipe can be painted different colors, or enamel, but the pipe "hot" water covered only a special paint, because paint is another water The high temperature starts to peel off. You must use a rosin varnish. One significant observation: color piping is necessary when there is no water in them, otherwise the paint and primer will not fully dry.
The main danger in the winter is freezing of water pipes. Due to the formation of ice pipes are corrosive processes that lead to defects and damage to water pipes. There are several ways to defrost pipes, consider some of them. Necessary to wet the cloth is very warm or hot water, wrap the pipe with a rag, after opening the valve to the water starting to melt, found out, but not pressed on the pipe wall, creating a risk of rupture. Slightly different way.
Open faucet, wrap the pipe with a rag and pour it out of the watering can with hot water. You can place the tube next to a small space heater. As a rule, all maintenance work on water pipes, held in the warm season. If you are in the pipeline itself, you must immediately take steps to protect it. It is better to cover the pipeline a mixture of cement and casein glue. After drying, a layer of varnish to cover it, and then oil paint. Based on materials rmnt.ru
The engine and generator are fixed to the frame via dampers. The generator is electrically connected to a flexible conduit frame. At the corner of the reference frame has a bolt to connect the ground wires. Launch generating sets and engine warming produced at the position of the handle 2 motor control at 1 / 4 … 1 / 3 full speed all the way from the top (the original position – PI). Exit at full throttle mode by moving control knob all the way down.
Tuning frequency current produced by the propeller. When you rotate it counter-clockwise current frequency increases with clockwise rotation – is reduced. To stop generating sets, you must install the control knob to the position of MG, work out 1 … 2 minutes and close the choke on the carburetor engine. Then, the control knob should be put in the IP. Emergency stop generating sets produced by closing the choke carburetor engine. After the engine stop control knob should be set to IP. In the most recent editions of the CD 5PE engines installed "Stop" button.
Before 1990 generating sets released 2g AB 2T/230 VPM and VPM AB 4T/230 ZZH with driving gasoline-powered DM 15 and DM 25. They are still used in the railway network of the country. These generating sets, as described above, have a block structure, articulated petrol engine with a generator with an aluminum flange. A single unit mounted on a tubular frame with four rubber bands. Mounted on the generator control unit with devices launchers, and a compounder regulatory resistance. Portability of the unit to produce a short-range forces of the two men. The unit can move one rail of railway track by two rollers mounted on the frame. Under the Regulations for Electrical Installation in mobile power is not recommended to ground the neutral of the generator. For safety reasons, the case of power tools have (with the fourth conductor power cable) in constant contact with a grounding device, the power plant. Ensure that the recommended grounding resistance 20 ohms at operating conditions is difficult and often impossible. Other ways to improve security (using the tool on 36 or motors with double insulation) due to technical complexity and cost far more in the production of no application. In connection with the those at the factory together with SIC COP (Obninsk) is designed and manufactured protective tripping device (RCD Zhou USP). Depending on the scheme can provide Zou control of isolation phase control fault ground, to make off with a decrease in insulation resistance below the permissible limits and thus prevent the development of emergency operation. For benzoagregatov types AB 2 and AB 4, as can be Zaw used the device with the simplest scheme. In contrast to conventional power generating set, equipped with Zoe, immediately terminate power supply in the following cases: reduce the insulation resistance below a pre- preset value, including power, cable and connected power tool;
Shotcrete. Gunned from the Latin. (Tec) tor (ium) – plaster, (con) cret (us) – Sealed – the method of concrete work, in which a concrete mixture in layers applied to the concreted surface under the pressure of compressed air, ie Mechanical application of concrete. Gunned by using shotcrete installation. Gunite – Installation MPCS 4 consists of concrete-syringe machines and compressors. Compressed air mixture of cement, sand, powdered supplements, fed through a hose to the nozzle, wetting it with water and with great speed 130-170 m / sec emitted by torkretiruemuyu surface. The layer thickness obtained in a single cycle shotcrete is 10-15 mm. Technical advantages Shotcrete: concrete layer a few centimeters from: high mechanical strength (for 28 days-40-60 M / na); density (2.4 kg / dm ); frost (at least M / ps 300); water resistant (not less than B12); High adhesion to the substrate.
Improved physical and mechanical properties of concrete: bending strength increased by 40%; compressive strength at 15%; elastic modulus at 5%; shrinkage to 30% less. Economic benefits Shotcrete: High performance. Low cost of operations. The use of shotcrete: Protect slopes and escarpments. Construction of the steep walled concrete structures.
Their life increases due to the absence of cracks. The thickness of the finish can be reduced because the shotcrete tight to the contour of the earth or rock foundations. Finishing of shotcrete has a higher strength at deformation, the best load distribution and stress, in comparison with conventional concrete finish.
The first lighthouse, set about a foot from the wall, the next – in inches 60 – 70 from the first, and so on. It depends on the length of rules, which will constrict. You can for example, the first set right along wall, the second – a meter away from him, the third – after another meter, so I think the idea of a handful of clutch ponyatna.Kogda (harden), you can begin grouting the floor, pre-moistened it with a roller. Priming is not necessary, it is possible just water, so as to dry the floor screed will not stick. To avoid unpleasant surprises, check out the joints between the floor and walls, if necessary – repaired something, even if foam. Otherwise, do not exclude the possibility to make repairs and even the neighbors below, with those at your expense. Solution for floor screed can be prepared from ordinary Portland cement not less than 400, and construction sand (in any case not a river!) In a ratio of 1: 3.
Rather, construction sand, sold in bags of 25 and 50 kg, it is usually also a river, but no shore, and extracted from the bottom, and the last major cleanup. And two big raznitsy.Rastvor not desirable to make a shovel in a bucket and mixer vedre.Poyasnyu.Kak would be nice to you not to stir the solution with a shovel, an ideal that can not be done in principle. Yes, you very likely obtain a homogeneous gray mass, but uniform in color does not mean that she has turned homogeneous in composition.
If necessary, apply chock tool (reeling out the ax, snap). The resulting product, in this way is called forging. Form, and the more weight forgings may vary (eg, weight forgings can up to 350 tons and more). The difference is that small and medium-sized forgings are made from rolled billets and large – from ingots. The most widely forged to get air and vapor-air hammers.
Small size of workpiece is treated with pneumatic hammers. The principle of a pneumatic hammer: there are two interconnected cylinders, the working and the compressor. In the role of the elastic connection acts air that is blown piston alternately in the upper and the lower part of the working cylinder, which drives the firing pin, which begins to strike the workpiece. Blows per minute firing pin can be anywhere from 95 to 225. Weight incident of this hammer can reach 1000 kg. Switchgear helps keep the striker at the top or bottom positions. Started work in the hammer with an electric motor.
Vapor-air hammers double actions are used for processing forgings of medium size, having a mass of up to 3 m. The falling of a hammer of mass 1 – 5 tons driven by steam power or compressed air, the frequency of beats per minute – 30 to 60. To work large forgings needed press – hydraulic or parogidravlicheskie. The principle of the hydraulic press is based on the law of Pascal. There is a transfer pressure of up to 20 MPa, was created in the working cylinder, the workpiece through the plunger, Traverse, the firing pin. Parogidravlicheskie different from hydraulic press so that they have a multiplier that can increase pressure to 60-80 psi. Water is supplied to the working cylinder of multiplier. Unique to the modern presses can handle bars up to 500 tons, because such media are operating force until 2000 meganyutonov. Designed to process the workpiece is placed between the movable upper and lower fixed strikers press or hammer. The direction of deformation, or, in other words, the flow of the metal blanks indicate the surface dies and bed-tools, which are in contact with him. When pulling cross-section of workpiece decreases and its length – is increasing. Billets have across dies, moves and Kant it 90 degrees after each compression. First forge a square, while the rate of deformation is the large, and then, if necessary, preparation or rounding the form. To speed up the curved broach used rolling and brisk, which increase the elongation of one compression. In the process of forging a metal workpiece in precipitation increased cross-section due to altitude. When bending the workpiece is clamped between the strikers hammer, you need a local heating of the workpiece. To obtain the same section and place the bend, and the entire length of the workpiece, pre-planting to do – draft of the piece. To flash the holes in the workpiece up to half its thickness proshiven hammered, then harvest should be reversed, and punch a hole through it. Barrel arbor helps to align or expand the hole. Otrubka done with axes. To smooth out small-scale forgings used trowels and large – with the help of light strikes the hammer dies. Can be used to furnish suitable crimping. You can understand even if you're a person, that the process of forging is not easy, but what we can contemplate the beauty in the form of a variety of forged products!