Tach water meters

Deynekin Viktor To account for consumption of hot and cold water in the Russian housing and communal services are most often used tach meters. Their basic element is an impeller, turbine, screw element, a ball or piston, rotating under the action of water flow. Number of turns of the element is fixed mechanically or magnetomechanical counter. Tachometer counters are pretty accurate, reliable, have a great working resource, easy to install, operate and maintain. All models are certified in Russia, have a guaranteed lifespan of at least 12 years. Calibration interval control accuracy meter installed by the manufacturer. Typically, this is 5-6 years for cold water meters and 3-5 meters for hot water. Price division tach meter ranges from 0,001 to 1.0 m3. Measurement error at different modes of water consumption ranges from 0.5 to 5% and is determined by metrological class of device, which is denoted by the letters A, B, C and D. Class A devices are only installed in horizontal pipelines, Class B, C and D - on the horizontal, vertical and oblique sections. When selecting the instrument should take into account the fact that there are models of counters, which are certified by the same class (eg, B), but when installed on vertical and inclined sections of the pipeline the accuracy of their testimony is a Class A. The manufacturer should specify it in the device data sheet. Depending on the maximum working pressure of the counter may be 1,0 or 1,6 MPa, but most devices can withstand short-term increase in pressure up to 2 MPa or more. If the rotation is transmitted to the counter mechanism directly to the impeller, the device is called a wet, because water gets into the counter. If the rotation is transmitted by means of permanent magnets, and water is separated from the counting device impenetrable barrier - dry. In the combined models of counters counting device cavity filled with a special paste-like substance. Sometimes in order to improve the accuracy tachometer counters are equipped with devices that share the flow of water into several streams. These counters are referred to as a multi. For pipes with a diameter of 15-20 mm is recommended to use single-jet meters, pipe diameter 20 mm - multijet. Counters to measure hot and cold water only differ in materials of construction for the working parts of the instrument. In cold water meters operating temperature range is from 5 to 50 ° C, the counter hot - from 5 to 90 ° C (sometimes up to 130 ° C and above), universal models - ranging from +5 to +130 ° C. Basically, the wing tach counters use the end users - they are placed in apartments and private homes, where the diameter of pipe water supply systems and domestic hot water does not exceed 15-40 mm. Counters are cut into the pipe with threaded components supplied by the manufacturer or installer. Schemes and rules of mounting a specific model of meter specified in its datasheet. Turbine tachometer counters are installed on the pipe diameter of 40 mm or more. As a rule, it introduces a system of water supply of apartment buildings, small enterprises, objects of cultural and domestic purposes, etc. Mounting the turbine meter is made using flanges. Reciprocating, screw and ball tach counters use a la carte principle of measuring the amount of water. They are harder and more expensive vane and turbine meters, and basically they are installed on the water supply system of elite houses. Counters of other types of pipelines with a diameter of 40 mm and a ring-mounted piston, vortex, electromagnetic, ultrasonic and other counters. These devices are designed for operation in water measurement units, designed for intensive water consumption, and includes devices for monitoring and control of pressure, temperature and flow rate. Ring-piston meters are characterized by high accuracy (0,01 l / h), which provides a special mechanism that combines the properties of the ring and piston flowmeter. Working parts, cameras, and the housing are made of stainless steel or high quality plastics. Typically, such meters are installed in buildings equipped with self-contained treatment systems and drinking water in the apartment. On the pipeline unit is mounted with threaded connections. Scheme water meter assembly 1 - Ball valve, 2 - Filter 3 - meter, 4 - ball valve with drain water when rounding the dense body in a stream of vortices are formed. Their speed is proportional to the rate of flow. Vortex meters measure the frequency and it determines the flow of water for pressure and temperature of the liquid. Typically, these devices are used to account for flow of gases or liquids with low viscosity (such as gasoline, kerosene, alcohol, water, etc.). Their cost is higher than the tach counters, and to exploit them can only highly skilled experts. Vortex meters should be used in cases where it is necessary not only to take into account water consumption, but also to control the flow and its parameters in real time. Electromagnetic (induction) counters are highly sensitive. They can be fitted not only to direct but also on curved sections of pipe. The meter measures emf that arises when water moves in a magnetic field device. The operating principle of ultrasonic (acoustic) count is based on determining the rate of flow by ultrasound. These counters are cut-in or overhead, and they must be connected to the mains. For induction, electromagnetic and vortex meter operating temperature range is determined only by the appointment of the device and can range from five to hundreds or more degrees Celsius. The high cost of the ring-piston, vortex, electromagnetic and ultrasonic meters limits their use to account for water in the Russian housing and communal services. Currently, the Russian market of all types of counters. The biggest demand is for units of domestic enterprises, "Rise", "Vodopribor", "Industrial services", "Sayan", "Centrpribor, Arzamas Instrument Plant and Western companies Siemens, Wehrle, Zenner (Germany), Premex (Slovakia), Yokogawa (Japan) , Metron (Poland), etc. The housing of large Russian cities and modern production facilities are increasingly being used counters able to read remotely. This allows you to automatically take into account water consumption in real time. To automate remote pickup tach reading meters are equipped with built-in (or overhead), pulse output - reed. This device converts the speed of the impeller to an electrical impulse that is transmitted by wire to the pulse counter, and then - in the control room, which can be removed from the device at a distance of 1,5 km. To transfer the meter data loggers are used in two basic principles: the formation of an electrical signal or pulse with frequency corresponding to the flow rate of the resource, and the formation of a digital code. In the first case, the signal can be transmitted over electrical wires in the second - by wire or radio. Using a reed switch can automatically take into account water consumption and remotely monitor the status of the pipeline - a leakage or rupture of the pipe, usually lead to a sharp increase in water consumption. Depending on the conditions of counters can be resistant to impact ("vandalozaschita"), waterproof, dustproof, etc. Almost all models are equipped with tachometer counters protection from exposure to magnetic fields. Some models are equipped with counters, built-in check valve protects the device from the power flow and water hammer, or connector to install it. Installation of meters is recommended to install meters in areas where exposure to the device of adverse factors (humidity, dust, magnetic field, etc.) will be minimized. If possible, the building is organized special ventilated room with its own entrance - water measurement site. Typically, these sites are located in basements or basement spaces, at least - in attics or in special annexes. In the modern apartment buildings hydrometric sites are organized directly during the installation of plumbing and heating systems. At the same time counters directly connected to the automated system acquisition and processing of data. Mount tach meter to the pipeline by means of threaded connections or flanges, in rare cases - by means of welding. For the installation of overhead meters use special fasteners that are supplied by the manufacturer. Front of the counter on the pipe mounted ball valve, and magneto-strainer, then - check valve with connecting elements (connectors, plugs, adapters, flanges, etc.). All elements are put arrows showing the direction of water movement. Brownies hydrometric sites are equipped with pressure gauges, thermometers, and additional valves, gate valves, bypass to control the pressure and temperature, electric remote flow control and other devices. All the tools for mounting the counter on a metal pipe are presented in a professional kit fitters, and mounting the device on Metal and plastic pipes need to use special tools, fixtures, mounting components and tools - welding machine, pipe cutter, special adhesives, sealants, fittings for connection plastic and metal pipes, etc. Before installing, you must take a census of the pipeline on its suitability for installation of water-measuring device or meter site. If the installation of the counter could lead to an emergency situation, from her must be abandoned. You also need to take into account the fact that the mass installation of water measurement sites increases the resistance of the water supply system. This can lead to increased pressure in the network and cause a rupture. Technological requirements for installing the counters before choosing a meter, measure the pressure in the network or to obtain relevant data in the organization operating the facility. Maximum pressure in the network must not exceed the pressure at which the counter is calculated. Failure to do so may cause damage to or destruction of water-measuring device node, and a breakthrough network. Temperature range meter should correspond to the temperature regime of the network. Otherwise the device will not provide the required accuracy and quickly goes down. Ball valve or cock shall be attached to the main pipe one-piece manner, that is, the pipe should be cranking closed-end portion of the crane or gate. In the case of a crane accident will not be disrupted and the user can override it by yourself. Fixing a ball valve or a valve from the demountable unit or by using a cap nut is unacceptable. Some models of the counters can be installed horizontally or vertically, others - only horizontally. This is stipulated in the passport unit. In the latter case, the vertical pipe will need to install special horizontal knee. When installing the counters in small apartments must take into account the length of the mounting device. All connections are water-measuring site should be carefully sealed. If the counter is supposed to build into the supply system of potable water or hot water, it must certify to the chemical (toxicological) security. Installation of water measurement sites is only acting and water-filled water, flushing and pressure testing in the past. Install water-measuring units in new buildings or water mains after the overhaul, repair, which were not carried out cleaning and pressure testing is unacceptable. Instruments carrying commercial accounting hot or cold water, must be protected from unauthorized changes and parse the counter. Consequently, they are sealed. Use lead or plastic seals and a special sealing twisted wire, excluding quietly remove the seals. All items subject to the sealing of water measuring site should have a so-called ears with holes for the wire. Hydrometric site must be sealed in such a way as to prevent any unauthorized disassembly. Reliability of water measuring node determines the reliability of its weakest element. Therefore, for mounting the device is recommended to use only certified products purchased from a reliable supplier and manufacturer of materials with high corrosion resistance (brass, copper, etc.). Information When you counter, consider the following: wing devices with nominal inside diameter of 15, 20, 25, 32 or 40 mm, manufactured by TU 4213-012-3219029-2003, designed to measure the volume of water SanPiN 2.1.4.1074, running in a system cold (5 to 50 ° C) and hot (from 5 to 90 ° C) water at pressures up to 1,6 MPa (16 bar). Domestic model counters shall comply with the requirements of GOST 50601 and GOST 50193, imported - the international standard ISO 4064. Counters are equipped with two types of indicating devices, shows the measured volume in m3 or m3, and its shares. On the resistance to temperature and humidity meters must comply with climatic design UHL (temperate and cold climate) location category 4.2 (GOST 15150). Counters for export must comply with climatic design TC (tropical dry) and TV (tropical humid) location category 2 and 3 (GOST 15150). Service in accordance with the contract service organization that ensures that water measuring site shall be at least one or two times a year to inspect all of its elements, to clean filters and sump, inspect the work taps, valves and valves, to eliminate leakage, replace the elements have cracks, chips or any other defects, validate manometers and thermometers, shoot and send to the repair of defective meters, replace appliances with depleted technical resource. If the device is connected to an automated system, removal of evidence must verify his statements and accounting of remote data. According to the results of each inspection shall be drawn from the findings of the technical state of water gauge site, and metering devices. For each water meter node is a schedule of maintenance work and gets the appropriate log which records all produced by the inspections and work. This approach provides a reliable and trouble-free operation of water measuring site. On the date fixed registration certificate, should be organized verify the accuracy of the counters. By arrangement with the suppliers and consumers of resources it may hold within the organization, ensures that water meter site, or specialized enterprises. After the verification should be granted an appropriate conclusion. Calibration can be performed without removing the device, by means of special ultrasonic, electromagnetic, etc., mobile devices, calibration or special stationary equipment