Methods of saving when conducting commercial metering of water and heat
Existing regulatory documents on accounting often contradict each other and have many weaknesses. So, the Rules for metering heat energy and heat carrier were approved only in 1995, but already now many experts recognize that they are morally obsolete. GOST R 51649-2000 "Heat meters for water systems, heat-
supply. General technical conditions ”was approved in 2000, but the test requirements set forth therein are not fulfilled. In particular, the devices do not pass electromagnetic compatibility tests. None of the test centers conducts the tests provided for by GOST for the purpose of checking security against unauthorized access to the memory of devices. Subsequently, to prove that the consumer deliberately distorts the readings of the devices is very difficult.
There are many possibilities for falsification. This is due to the fact that the heat meter is quite complicated in terms of device, operation algorithms, installation, operation.
There are a number of ways to correct instrument readings. The easiest way is sometimes used by homeowners to reduce the cost of water used for irrigation. The consumer buys the cheapest and most unreliable (according to the reviews of neighbors and friends) water meter, agrees its use with a water supplier. In accordance with domestic standards, the minimum flow rate recorded by the water meter is 30 l / h. Therefore, the valve opens so that the flow rate is less than 30 l / h. At the same time, the meter does not record water analysis at all, that is, by installing the device, the consumer is able to legally not pay for water: at a flow rate of, for example, 20 l / h, you can get 480 l of clean drinking water for a day absolutely free!
In urban apartments, residents practice a slightly more complicated way. When installing the meter, it is necessary to install a strainer with a stopper that is not sealed, since the filter needs to be cleaned periodically. The consumer twists a flexible hose (inlet) into place of the removed filter drain nut and receives water bypassing the meter. If the inspector of Vodokanal arrives to check the meter (which happens very rarely), it is enough to unscrew the nut of the hose and put a standard plug - this takes several minutes.
For the same design of the water metering unit, there is a simpler way: a thin wire is attached to the strainer glass and passed into the pipe along the water. The wire slows the rotation of the counter impeller, and the readings are significantly underestimated.
Most of the water meters currently in use are the so-called “dry waste”. They consist of two parts: a turbine rotating in water, and a counting mechanism, separated from the turbine by a sealed partition. One or several small magnets are mounted on the impeller. Water rotates the impeller; under the influence of the rotation of the magnets, a metal ring rotates behind the sealed partition; the rotation of the ring is transmitted to the counting mechanism. The essence of the following method of understating readings is the braking of the impeller by installing external magnets, the position of which is determined empirically.
The considered methods for correcting the readings of water meters compel a somewhat different attitude to the positive conclusions of various organizations on the results of their implementation. It is clear that if you install apartment water meters in a residential quarter, then the sum of their readings (for example, for a month) will be less than the calculated value determined by the relevant standards. This is not in doubt. However, in neither of the reports, nor in any of the numerous articles, the authors did not meet the mention that somewhere after the installation of apartment water meters the total water consumption of the city, region, village decreased. In practice, at the same time as the introduction of water meters, the imbalance between the results of recording vacation and consumption is growing, and the manipulations with the devices discussed above are compelled to be attributed to losses in distribution networks.
More diverse are ways to adjust the readings of heat meters. The heat meter consists of three main blocks: a flowmeter, thermal converters, a heat meter, and corrections can be made by manipulating any of the blocks.
Tachometric flow meters of heat meters have the same adjustment options as those mentioned above for water meters.
The electromagnetic flowmeter is structurally composed of two magnetic coils mounted under and above the pipe, two measuring electrodes arranged horizontally. An alternating voltage of known frequency and shape is applied to the coils. A signal proportional to the flow rate is taken from the electrodes. To correct the readings of the device, additional magnetic coils are installed outside the flow sensor, the voltage of which is supplied in antiphase to the voltage of the device coils. Thus, a useful signal is suppressed and readings are underestimated. Fortunately, this method has not yet received wide distribution, since it requires a certain qualification of the performer.
The vortex flowmeter structurally consists of a triangular prism vertically mounted in the pipe, a measuring electrode inserted into the pipe downstream of the liquid, and a permanent magnet mounted outside the pipe. Manipulations are reduced to a distortion of the magnetic field of the permanent magnet of the flowmeter. To do this, use a set of permanent magnets.
Their location is chosen empirically. In this way, it is possible to significantly raise the lower limit of the measuring range of the device. Another way to underestimate the readings of vortex flowmeters is to swirl and swirl the flow of water, for example, by shifting the gasket between the flanges of the device and the pipeline during installation.
A simple but effective way to underestimate the readings of a heat meter is associated with the operation of thermal converters. They are installed in the supply and return pipelines and connected by communication lines to the heat meter. By connecting a resistor with a variable resistance in parallel to the thermal converter installed on the supply pipe, you can lower the temperature of the water supplied from the heating system. Moreover, the magnitude of the required "savings" is governed by the selection of resistance of the resistor.
Method of unwinding a water meter using a vacuum cleaner
When installing the meter, a mesh filter with a stopper is usually installed in front of it, which is not sealed. From time to time it is necessary to clean it. At this point, it is convenient to time the "unwinding" of the counter. The idea is simple - to pass through the counter the flow of something (preferably free) in the opposite direction. We use air for this. So, close the valve in front of the filter and remove the plug from the filter.
We take a vacuum cleaner, insert its hose into the outlet (if the design of the vacuum cleaner allows this) and “blow” it, for example, into a window (to remove dust).
We open the tap on the mixer and connect the hose from the vacuum cleaner to it. The connection can be sealed, for example by wrapping a cloth around the mixer spout or by holding the connection with your hand. Part of the air will still have to be released so as not to burn the vacuum cleaner.
Turn on the vacuum cleaner and turn the counter back. The speed is adjustable by releasing part of the air at the connection point of the vacuum cleaner hose to the crane. This must be done, otherwise the vacuum cleaner may burn out due to lack of air to cool the engine. On domestic taps, it may not work, since they have a gasket attached to the stem freely and can act as a check valve.
This method is applicable if the vacuum cleaner is old type. New ones can only “suck”. In this case, we connect it to the filter instead of the plug. You only have to watch so as not to "pump" the water remaining in the pipes. Otherwise, the vacuum cleaner will fail. To avoid this, you can use a separation vessel. To do this, take a jar, close it with a plastic lid, make two holes in the lid. The hose from the vacuum cleaner should be inserted tightly into one (shallow), the hose going to the filter also tightly into the other (this hose is inserted almost to the bottom of the can). Now water, accidentally left in the pipe, will be collected in the bank, and clean air will go into the vacuum cleaner. (Anna 01/03/05)
The method of stopping the water meter using a magnet
The use of a magnet to stop the SGV-15 water meter. Two magnets from the speakers glued to the plate with a hole through which the entire device is worn on the meter body. It has been tested that the magnets used in the computer’s hard drives are stronger and installed simply on the glass opposite the axis (simply attached) generally stop the counter.