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how to stop the wind off gas meters
Household and municipal gas meters, manufactured by industry:GBS-G2, 5, G4-1 (JSC "Signal-to-device")
GBS-G2, 5, G4 signal (JSC "Signal-to-device")
GBS-G6 (JSC "Signal-to-device")
NPM-G1, 6, G2, 5, G4 (JSC "Gazdevice")
Gallus 2000 G1, 6, G2, 5, G4 («Actaris»)
G6-RF («Actaris»)
G10, G16, G25, G40 («Actaris»)
BK-G1, 6, G2, 5, G4 (LLC "ELSTER RusGazPribor")
BK-G6, G10, G16, G25 (LLC «Krom Schroder»)
SGK-1, 6, -2.5, -4 (VPO FSUE "Tochmash")
SGK-4-1 (JSC "appliance")
RL-4, -6 (OJSC "Ivano-Frankivsk plant" Prompribor '")
RGA G10, G16, G25 (OJSC "Ivano-Frankivsk plant" Prompribor '")
WGA-Ex G10, G16, G25 (OJSC "Ivano-Frankivsk plant" Prompribor '")
"Berestye" T2, 5, KG4 (LLC "BEMKROMGAZ")
"Berestye" G4, G6 (LLC "BEMKROMGAZ")
SGBV, a G4, G6 (UE "Minsk Mechanical Plant. Vavilov")
SGBV-1 G6 (LLC "Novogrudok plant of gas valves")
SRS-2, 5 (OOO "Novogrudok plant gas fittings")
MCM G4, G6 («Premagas»)
UBSG-001 G6, G10 (JSC "Gazdevice")
LIS-1 (SUE "SSPE" Fusion "")
SG-1 (JSC "Relero" (NPO. Popov))
KG-2 (G1, 6) («KumHo Metertech»)
Membrane (diaphragm, tube) gas meters
Diaphragm meter (orifice, the chamber) - the gas meter, the principle of action is based on the fact that with the help of various mobile elements converting natural gas share in the volume fraction, and then produce their cyclic summation.
Orifice meter (see Figure 8.10) consists of a housing, a cover 2, the measuring mechanism 3, the crank-lever mechanism 4 connecting movable parts of the diaphragms (membranes) with the upper valve timing unit 5, the valve seat (lower part of the switchgear) and the counting mechanism . Housing and cover meter can be:
- Steel, extruded, coated against corrosion and sparking. Connection stamped steel body and cover performed by shrink sealing material and the band 6 (see Fig. 8.10), which provide a snug fit two parts together;
- Aluminum, cast. Housing and cover with aluminum counter performance hermetically sealed with special seal and a set of screws, one screw seal is made. Details and components of the measuring mechanism for membrane counters are made of plastic. The use of plastic measuring mechanism significantly reduces the cost of production, increases the resistance to chemical components in gases, reduces friction in moving parts counter.
Depending on the design and the measured gas volume measuring mechanism may consist of two or four cameras. Schematic diagram of the orifice meter is shown in Fig. 8.11.
In Fig. 8.10. Orifice meter: 1 - housing 2 - Cover 3 - measuring mechanism, 4 - crank-lever mechanism, 5 - upper valve timing device 6 - shrink band
Position cameras meter | Camera 1 | Camera 2 | Camera 3 | Camera 4 | ||
and | Emptied | Filled with | Empty | Filled with | ||
b | Empty | Filled with | Filled with | Emptied | ||
in | Filled with | Emptied | Filled with | Empty | ||
Mr. | Filled with | Empty | Emptied | Filled with | ||
In Fig. 8.11. Schematic diagram of the orifice meter
The counter works as follows:
a) The measured gas flow through the inlet pipe enters the upper body cavity and then through the open valve into the chamber 2. The increase in the volume of gas in the chamber causes the displacement of the diaphragm 2 and the displacement of gas from the chamber 1 to the output of the slit valve seat and then into the outlet count. After approaching the lever aperture of a diaphragm wall of the chamber is stopped by switching valve groups. The moving part of the valve chambers 1 and 2 completely covers the valve seats of these cameras, disabling this camera unit.
b) The valve chambers 3 and 4, gas inlet opening in the upper cavity of the body count in the chamber 3, fills it, which causes movement of the diaphragm and displacement of gas from the chamber 4 to the outlet through the cracks in the valve seat. After approaching the lever aperture of the diaphragm wall of the chamber 4 is stopped by disabling the valve unit cells 3 and 4.
c) The valve chambers 1, 2, opens the gas inlet of the upper cavity of the body count in the chamber 7. When applying the gas in a chamber diaphragm 1, 2 moves, displacing the gas from the chamber 2 to the output gap in the lad through the valve seat. After approaching the lever aperture to the chamber wall 2 aperture stops in the valve block off from cameras 1 and 2.
g) The valve chambers 3, 4, gas inlet opening in the upper cavity of the body count in the chamber 4. When submitting gas chamber 4 aperture 3, 4, and moves
displaces the gas from the chamber 3 to the outlet through the cracks in the valve seat. After approaching the lever aperture to the chamber wall 3 aperture stops as a result of off valve unit 3 and 4.
The process is repeated periodically. Counting mechanism counts the number of moves the diaphragms (or number of cycles of the measuring mechanism n). During each cycle the volume of gas displaced V n equal to the sum of the volumes of chambers 1, 2, 3, 4. One complete revolution of the output axis of the measuring mechanism corresponds to 16 cycles.
Method of inhibition:
Must be removed from the gas meter (there is not always able to restore the seal on the cap nut)!!
The essence of the method to be depressingly simple - inside the outlet pipe connections must be leakproof plastic insert and the body count. I just straightened a little plastic screwdriver and teased into a sealing O-ring tweezers and removed it the result surpassed all expectations, the counter turns half.
I understand this type of meter is very sensitive to the pressure drop of gas input-output after this procedure can be part of the sealant stick to the place, and then I turned on the gas stove when he is not turning the poor fellow ....
Began to be considered only when the gas boiler. Well, that's all. After that, put a counter on a regular place and restore the seal.
Sergei Frolov.
Turbine gas meters
In the gas turbine meter (Figure 8.13) under the influence of gas flow turbine wheel is rotated, the speed is directly proportional to the volume of flowing gas. Speed through the turbine reduction gear and the gas-tight magnetic coupling is transferred to the gas chamber is located outside the counting mechanism, showing (by increasing) the total volume of gas at operating conditions, passed through the device.
In Fig. 8.13. The scheme of the turbine gas meter SP: 1.10 - measured by the cross-section, 2 - pressure switch, 3 - magnetic clutch, 4 - counting mechanism, 5 - termoizmeritelny probe PT-100, 6 - check the thermometer, 7 - output channel, 8 - Sensors pulses, 9 - turbine wheel, 11 - the displacement body
At the last cogwheel gear mounted permanent magnet, and near the wheels - two reed switch contact closure rate is proportional to the first rotational speed of the turbine rotor, ie, the gas flow rate. When a strong external magnetic field, the second reed switch contacts are closed, which is used to signal the unauthorized interference.
Structurally, the turbine meter, manufactured in Russia, represent a segment of pipe flanges, in which the flow path in series along the flow inlet flow conditioning plate is located, the node with the turbine shaft and the bearing supports rotation and back support. On the body count mounted oil pump plunger assembly, by which the bearing area of the tubes is fed liquid oil. At the turbine casing provides a place for the sensor devices (to measure pressure, temperature, pulse).
According to the degree of automation of the process of measurement and processing of measurement results turbine meters are available in the following trim levels:
- For the separate measurement of the variables monitored parameters with an arbitrarily selected by means of processing the measurement results (calculating device manual actions, calculator, etc.);
- For semi-automatic measurement of the variables monitored parameters with the computational processing units of measurements and devices with manual entry of values of quasi-constant parameters or manual correction of measurements and calculations;
- For automatic measurement of all parameters being monitored with the computational processing units of measurement results.
Rotary gas meters
With the increase in types of equipment was necessary in measuring instruments, which would possess a relatively large bandwidth and large measurement range with a relatively small footprint. These conditions are satisfied rotary gas meters, which have the following additional advantages: no need for power, durability, ability to control the correct operation of the pressure drop on the counter while it is running, the insensitivity to short-term overloads. Rotary meters are widely used in public services, especially in heating plants, as well as small and medium-sized enterprises.
Rotary (rotary) counter - chamber gas meter, which as a transformative element used vosmiobraznye rotors.
The rotary type gas meter WG consists of a shell, inside which rotate two identical vosmerkoobraznyh rotor 2 and a countable transfer mechanisms associated with one of the rotors. The rotors are rotated under the influence of differential pressure gas supplied through the upper inlet and outlet through the bottom outlet. When you rotate the rotor run-in their lateral surfaces. Synchronization of rotor rotation is achieved by two pairs of identical gears, mounted on both ends of the rotors in the end boxes outside the measuring chamber-corps. To reduce friction and wear of rotor pinion permanently lubricated, encapsulated in the end box.
The volume of gas displaced by a half-turn of one of the rotor is equal to the volume bounded by the inner surface of the body and the lateral surface of the rotor, which occupies a vertical position. For a complete turnover of the rotors replaced four of these.
In Fig. 8.12. The rotary gas meter type WP: 1 - case 2 - the rotor
In the manufacture of rotary meters particular attention is drawn to the smooth running of rotors and a decrease in noise-leakage of gas through the meter. Ease of travel, which is a qualitative indicator of low-friction in the mechanism, and hence a low pressure loss in the counter, by installing two rotors on ball bearings, reducing to a minimum of friction in the gearbox and the counting mechanism, as well as the rational choice of design size and speed of the rotors. Reduction of gas leaks is achieved thorough treatment and mutual adjustment of the inner surface of the body and the rubbing surfaces of the rotors. The gap between the hull and rectangular pads located at the ends of the largest diameter rotors, ranging from 0.04 to 0.1 mm depending on the type of counter. In the manufacture of counters, special attention is paid to the static load balancing and handling of the rotors.
Vortex flowmeters
Vortex flowmeters are called based on the flow rate depending on the pressure fluctuations arising in flow in the vortex of the jet or fluctuations, or after some form of barriers installed in the pipeline, or a special twist thread.
The name of the vortex flowmeters have received from the phenomenon of vortex shedding, resulting in the flow stream of fluid or gas barriers, usually in the form of a truncated trapezoidal prism (Figure 8.9). Behind the body the flow sensor is perceiving the vortex fluctuations.
The advantages of vortex flowmeters are: no moving parts, independent readings of pressure and temperature, a wide range of measurement, frequency measurement signal at the output, the possibility of universal calibration, a relatively small cost, etc.
The disadvantages of vortex flowmeters include a significant loss of pressure (30-50 kPa), limits the possibilities of their use: they are not suitable for low velocities of flow, to measure the flow of contaminated and aggressive media.
In Fig. 8.9. Diagram of the primary vortex flow transducer (SI - pulse counting device)
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