Of asbestos-cement pipes

First, the Asbestos general. It is a natural mineral, magnesium hydrosilicates. Depending on the impurities and the structure forms a variety - chrysotile, (it's not a typo, not Peridot, namely chrysotile!), or white asbestos and amphibole asbestos. Asbestos was never a radioactive or poisonous touch and close proximity to it is perfectly safe, but inhaling asbestos dust often long hours and should not - in some people with prolonged exposure to high concentrations of asbestos dust may cause malignant tumors in the organs of respiration. No other cancer asbestos does not cause. more active in this against acid amphibole asbestos, so they are forbidden not only to use, but mine. It is because of the remote negative consequences of uncontrolled use of amphibole asbestos in combat ships during the Second World War in Europe and have a reason to negative with respect to any asbestos. chrysotile asbestos fibers, not having resistance to acids, get into the lungs, partially dissolved and partially printed. The half-life - approximately 10 days. For the same fibers of cellulose (a natural vegetable fiber, such as wood dust) during this period thousands of times more. In the future we'll discuss the asbestos products, where asbestos fibers are chemically bonded with cement (packed in a cement matrix) and therefore have quite different properties, they are simply safe. Actually asbestos dust using asbestos materials are released. The use of asbestos in the building from a medical point of view is determined by the hygiene regulations GN 2.1 .2/2.2.2.1.1009-00 approved by the Ministry of Health of the Russian Federation in 2001. Any risk should be assessed reasonably: none of us would agree on the spot to drink a bucket of very clean and healthy water, but we all do not hesitate to go of course carcinogenic asphalt, inhale carcinogenic fumes of cars, smoke, eat salted and smoked fish ... All of these products in the list of carcinogens are far ahead of the asbestos! The company "Suholozhskasbotsement (Sverdlovsk region) daily contact with asbestos are more than 700 people. oncological diseases there not had any in the world today laid 3,000,000 kilometers asbestos pipes, one in Russia - more than a million. Sizes of asbestos-cement pressure pipes are determined by GOST 539-80, test methods - GOST 11310-90. In Soviet times, asbestos cement pipes were severely Funded material and used almost entirely in the reclamation facilities. State regulations on the use of asbestos cement pipes in industrial and civil engineering was not simple. With the collapse of the Soviet Union there was a real possibility of widespread use of asbestos pipes at construction sites in Russia, which demanded the establishment of regulatory framework. First , was re-snip thermal network. The text snip 41-02-2003, paragraph 10.3. the parameters of the coolant, which allows the use of networks of non-metallic heat pipes - this pressure is not more than 1,6 MPa and a temperature not exceeding 115 C. Item 10.4. allows the use of non-metallic pipes in both open and closed systems, hot drinking water. SNIP 2.04.02-84 * Water. External networks and facilities. paragraph 8.21. defines the asbestos cement pipes, as the basic material for pipes of cold water and requires additional justification for the use of metal tubes. Finally, in 2006, was reprinted rulebook SP 41-106-2006 Design and installation of underground piping heat and hot water from asbestos cement pipes. The main differences of this new edition: a) the possibility of asbestos-cement pipes in the networks of objects not only the third but the second category of reliability of heat - ie, for heating homes and public buildings, and it is - a breakthrough, the emergence of real market opportunities for producers and seriously save for advanced designers and builders, and b) stated in a joint venture 41-106-2006 lifetime of heat from the asbestos cement pipes - 25 years has need to confirm the efficiency of rubber seals in the wild. Moscow Research Institute of elastomers has completed work on the development and testing of O-rings from heat-resistant rubber, and c) "legitimized" construction sites of special bends, elbows, transitions from one diameter to another, out of the ground, etc. For more details - see below; r ) in the SNIP 41-02-2003. Thermal network. briefly mentioned in relation to steel pipe designed to VNIPIenergoprome (Moscow) penopolimermineralnaya insulation. The SP 41-106-2006 penopolimermineralnaya teplogidroizolyatsiya first applied to asbestos cement pipes. Its main difference from all other - properties that are close to the polyurethane, but the production on the surface a semi-permeable crust with a load capacity of up to 12 kg/cm2. This crust does not miss a monolithic insulation moisture from the outside, but during the operation allows the insulation to get rid of water vapor. High peel strength makes it possible to lay pipes insulated ductless. NIItraktoroselhozmash JSC (Chelyabinsk) has approved and registered with the specifications and process requirements for penopolimermineralnuyu insulation for asbestos-cement pressure pipes, made an experimental batch of pre-insulated asbestos cement pipes. It should be said about the cost - in contrast to the polyurethane foam insulation is not needed shell of plastic sleeves and in the insulation - more than 40% by weight of cheap construction sand. The cost of materials for insulation meter of pipe DN 100 mm does not exceed 300 rubles. In view of the RF Law "On technical regulation" enterprises producing asbestos products, the requirements for their products and services specifications. Asbestos cement pipes are available in length 3.95, or 5 meters and a bore 100, 150, 200, 250, 300, 400 and 500 mm. In Soviet times the area of ??Simferopol was laid conduit length of about 20 km of pipes with a bore of more than 700 mm, but the manufacture of large diameter pipes technologically more difficult. Asbestos - a fibrous concrete, ie, fiber reinforced concrete. Obtained from the exploration and production company asbestos mechanically crushed and fluffs up the fibers division, in an amount of 15% to 85% mixed with cement and water is added. The resulting slurry is poured onto a mesh drum, and wrung the film thickness of 0.2 mm and a width, the length of the next pipe is wound on the rolling pin, ensuring the necessary thickness of the wall and, hence, the strength of the pipe. In the process of manufacturing pipes asbestos fibers are oriented primarily along the tangent, which provides high strength with loading by internal pressure. "Suholozhskasbotsement" (city of the Sukhoi Log, Sverdlovsk reg.) Since 1937, produces pressure pipes, particularly for water pipelines DN 100 mm for a working pressure 1,6 MPa, ensuring efficiency at 150 C. This pipe when tested to destruction of the internal pressure withstand at least 5.8 MPa, and a sample length of 200 mm crushing load of at least 1600 kg. Any type of asbestos product plants is accompanied by sanitary-epidemiological conclusion - a dangerous product on the market is not available. The ends of each pipe to the outside diameter of stitch to get the exact size and a given roughness. Pipe joints in the pipeline is made using asbestos as couplings with the inner surface of the groove with established in them by elastic rubber rings. The rings have a complex cross-section - similar to the cuff - and under the water pressure in the pipe is securely tightened to sealing surfaces. At the junction of the pipe and coupling provides a guaranteed radial clearance, which allows for elastic deformation of the rubber gasket bend pipe up to 3 degrees angle in each compound. Mounting the gap between the ends of pipes eliminates the need for temperature compensators. Asbestos cement has a coefficient of thermal elongation of 12 times less than steel. Five-meter asbestos-cement pipe is heated at 100 C is extended by only 0.4 mm. In addition, each end of the tube elastically deforms the rubber ring on the 0,2 mm. Coefficient of thermal conductivity of asbestos in 140 times less than steel, but asbestos pipe wall thicker than that of steel, three ... four times. Therefore, asbestos-cement pipe permits the use of simplified thermal insulation - Charging (expanded clay, slag). And in the case of polyurethane foam insulation layer it is three times thinner than a steel pipe. For example, for pipes DN 100 mm, enough with 14 mm polyurethane foam. Improved thermal insulation - penopolimermineralnaya. It is intended for ductless installation, but it does not require hermetic containment of polyethylene due to their properties without the need for a complex system of dispatching control of the state of moisture insulation. Asbestos cement is a good insulator, so the asbestos pipes, and even divided by five-meter section of electrically rubber rings are not subject to electrochemical corrosion under the influence of stray currents and do not need waterproofing. Therefore, they do not like for like replacement for the pipelines in industrial zones, urban areas with electric transport and railway stations, where all the line stretched along the paths. Under these conditions, steel pipes are only about two years, most fully the economic benefits of asbestos-cement pipes are realized for ductless strip - do not need trays, eliminating the need for waterproofing and cathodic protection, do not bother with mineral wool insulation in the trench or binding on the SNIP system dispatching moisture control insulation in the case of polyurethane foam. The current technology for manufacturing asbestos-cement pipes, allow only straight-line products. Of course, from asbestos-cement slurry can be cast in a mold of any tee or crossbar, but asbestos fibers in them are arranged randomly, rather than directed, and the strength of such products can not speak. Therefore, all the shapes in the asbestos cement pipes have traditionally been steel. At the point of transition from asbestos to steel used flanged gland seals. The need for waterproofing and fixing of steel "fasonki" to a fixed support forced on every challenge, or rotating route of the asbestos-cement pipes to build the thermal camera. NIItraktoroselhozmash JSC (Chelyabinsk) has developed and patented the normal, which is a set of special units - concrete reservoirs, "cubes," which is flooded and the entire "fasonka, ending at the end surfaces of the collector standard asbestos cement couplings. Corps collector, from the extensive surface plays the role of fixed supports, the concrete protects the steel from moisture and reduces heat loss. Possible in such a reservoir host is not steel, and plastic molded parts - then do nothing to corrode. Even when corrode steel shaped elements special node will continue to work - because the channel in the concrete will remain unchanged. Referred to the normal is versatile enough - Contains headers for different pipe diameters, the transitions from one diameter to another, turns, bends, exits out of the ground for installation and dismantling joints, sitting down with rubber rings to seal the pipe surface with a noticeable interference fit, engineered and tested mounting tools . Now the work is "third generation", the most perfect of the manual. If necessary, trim the pipe can be used hacksaw. But running tap end of the pipe to seal it in the sleeve - the problem. Common lathe 16K20 works with the workpiece length little more than a meter, and then only with the backrest (additional support). And if the pipe length of three meters and a half? These machines are not on every plant you will find! We have also patented a device that allows after adjusting for the length right on the edge of the trench by hand for a couple minutes under running tap seal the end of the asbestos-cement pipe in any length, just as the sharpened pencil sharpener. Few of the economy. Steel welded threaded pipe DN 100 mm is now about 280 rubles. / M. A similar, but asbestos-cement - about 70 rubles. / M (the selling price of the plant). Underground ChannelFree ™ pipeline from asbestos-cement pipes (if the little turns and bends) is three times cheaper than steel. Project-specific reconstruction of the underground heating two-pipe DN 300 mm length of 70 m: the difference in the cost of replacing the steel pipe to steel or asbestos-cement amounted to 250 thousand rubles. This is the cost of repairs, and ahead - operating costs, which for the asbestos cement pipes is three times smaller. Asbestos heating have been successfully operated in Kursk, Belgorod. In the Urals - in Miass and in Chelyabinsk. In Chelyabinsk Oblast Ministry of Construction in February 2005 reviewed the application of asbestos-cement pipe at a meeting of scientific and technical council and approved their use in conjunction with technology, "Trubokomplekt" proposed by JSC NIItraktoroselhozmash. In June 2005, based on the Ministry of Construction of the Sverdlovsk region was held a training seminar at which the topic of the asbestos cement pipes has caused great interest. Local heating network DN 100 mm in length 125 meters on the market of building materials "Brick" (Chelyabinsk, a private investor) could reduce capital costs in 1050 rubles. to 600 thousand rubles. For four seasons exploitation No comments were not. Remarkably worked for two heating seasons reconstructed sections of heating in the village-automatic mechanical plant (Chelyabinsk, DN 100 mm, length 77 and 130 m, the municipal heating network). For the first time in many years, snow does not melt on heating mains, heat in the houses was applied continuously. In 2006, implemented a contract for the reconstruction of heating on the electric locomotive factory (RW CFR), the season has passed without comment - the benefits of asbestos-cement pipes are a real application. Today's market offers a great variety of various pipes - just steel, steel with different coatings, stainless steel, pipes made of nonferrous metals, plastic, metal, ceramic, high-strength nodular cast iron, which is even slightly deformed without being destroyed. There is only one pipe - universal for all cases - cheap, everlasting, easy to install in all conditions. Probably, the universality of the complex and contradictory conditions unattainable. Therefore, an exhaustive and objective information about all the pipes in general, to correctly identify precisely the one the only one we claim that in the water, hot water supply, sanitation, and particularly for heating, in the village networks, railway stations, in the intra-wiring with diameters up to 200 ... 300 mm asbestos cement pressure pipes for no capital costs or operating costs of today there is no alternative!