Woltman Water Meter

1. What’s the Woltman water meter？

The Woltman water meter, also known as the screw-type water meter, is a velocity water meter. It is suitable for use in large diameter pipelines (DN 80 – DN 200). It is characterized by its large circulation capacity and low-pressure loss.

2. What’s the working principle of the Woltman water meter？

When the water flows into the water meter, along the axis of the direction of impact on the water meter screw-wing-shaped impeller rotation after outflow, the impeller speed is proportional to the speed of water flow, after the reduction gear drive, in the indicator device to show the total amount of water through the water meter.

3. What are the classifications of the Woltman water meters？

There are two main types of Woltman water meters: horizontal and vertical Woltman water meters. Most of the industrial meters used in China are flat screw-type water meters. In addition, the detachable flat Woltman water meter (dry type), because of its wide range of measuring flow, strong versatility of parts, installation and maintenance can be carried out without stopping the water without dismantling the meter, and other characteristics have also become one of the series of products and welcomed by users.

Horizontal Woltman water meter, also known as turbine type water meter, means that the axis of the screw wing of this water meter is parallel (or overlapping) with the axis of the water pipe, and its impeller adopts the shape of a screw wing. This does not mean that this type of water meter can only be installed horizontally. But, of course, suppose this kind of water meter needs to be installed vertically. In that case, it should be selected into the water side of the screw wing shaft bearing hole with a gem end flat bearing water meter to reduce friction resistance and extend the water meter’s service life. Some imported models of screw-wing water meters use dynamic balancing technology and can work in horizontal, inclined, and vertical states. Still, the measurement level of the meter should be reduced by one level when working in non-horizontal conditions.

Vertical Woltman water meters are suitable for water metering in applications where the flow rate varies considerably. Its vertical screw internal structure, wide measuring range, and high accuracy, R=200, is the preferred water metering apparatus for water resource management and charging departments. It improves the economic efficiency of water resource management through accurate measurement and reduces water waste. Moreover, it is very convenient to upgrade the intelligence, only need to replace the upper casing with a different telemeter module, can complete the intelligent upgrade transformation, is the water resources management department preferred large-diameter water meter, screw wing type high-precision large-diameter water meter.

4. What is the construction diagram of a Woltman water meter?　　

The horizontal Woltman water meter means that the axis of the screw wing is perpendicular to the axis of the water main.

The structure is shown in the diagram:

• flat washer; 2-bolt; 3-copper wire; 4-lead seal; 5-cover assembly; 6-instruction mechanism; 7-glass; 8-cover liner; 9-seal gasket; 10-movement; 11-O-ring; 12-case; 13-shunt ring; 14-gasket;

The vertical Woltman water meter’s screw wing is supported vertically, so its wear resistance is better than that of the horizontally screwed winged bushings. As a result, the small flow measurement capacity of the vertical Woltman water meter is more vital than that of the horizontal Woltman water meter.

The structure is shown in the diagram:

1 – case; 2 – adjuster; 3 – copper wire; 4 – lead seal; 5 – sealing gasket; 6 – backing ring; 7 – indicating mechanism; 8 – gauge glass 9 – hood assembly; 10 – watch cover; 11 – wing wheel assembly; 12 – bracket assembly; 13 – rectifier assembly; 14 – slotted cheese head screws

4. What are the technical indicators of the Woltman water meter?

I. Allowable working pressure: 1Mpa.

II. Allowable temperature: 40℃ for cold water meters and 90℃ for hot water meters.

III. Measuring characteristics: the maximum permissible error in the low zone from including the minimum flow rate to excluding the dividing flow rate is ±5% for cold and hot water meters; the maximum permissible error in the high zone from including the dividing flow rate to including the overload flow rate is ±2% for cold water meters and ±3% for hot water meters.

5. What are the characteristics of Woltman water meters？

Horizontal Woltman water meters：

Horizontal screw-wing water meters are used to measure the total volume of water flow in high flow pipes. It is particularly suitable for water supply mains and large factories and mines for water consumption. The main characteristics are large circulation capacity, small volume, compact structure, easy use, and maintenance. The specification stipulates that the installation of the screw-wing water meter, the front of the meter, and the cold door should be not less than eight times the diameter of the water meter interface, at least 5D before and 3D after, the primary purpose of the required straight pipe length is to ensure the stability of the water flow, because the basis for ensuring the accuracy of the water meter is that the water flow is in a stable laminar flow state.

Vertical Woltman water meters:

I)Easy to maintain, the movement can be dismantled and replaced, maintenance is very convenient.

II)Intelligent and easy to upgrade, only need to replace the cover to upgrade to a remote water meter.

III)Low power consumption design. When upgraded to wireless remote transmission type, the battery can be used for 2~3 years, and the battery voltage can be viewed in real-time through the management software for easy replacement.

IV)When upgraded to wired remote transmission M-BUS/RS485 type, the normal working condition is powered by the communication line, and the built-in lithium battery can ensure the normal measurement of water meters for more than three years when the communication line is broken.

V)Remote meter reading: through the management software, the usage data can be read at regular intervals so that the water consumption can be monitored in real-time and abnormal water consumption can be easily detected and investigated.

VI)Excellent moisture resistance, passed IP68 waterproof level test, can be used with confidence

6. What are the precautions for installation use and maintenance？

I) Wire requirements.

(Wires between water meter and collector) Distribution meter: use a cross-sectional area greater than or equal to 2 x 0.5mm2 copper core wire or network wire; RS485 bus direct reading water meter: use a cross-sectional area greater than 2 x 0.75mm2 copper core sheathed parallel wire for the power line; use 2 x 0.5mm2 copper core twisted shielded wire for the RS485 signal line.

C-Mbus bus direct reading water meter: within 500 m distance, use copper-core twisted shielded wire with a cross-sectional area of more than 2×0.75mm2 copper core; outside 500 m, use copper-core twisted shielded wire with a cross-sectional area of more than 2×1mm2 copper core.

II) Wiring requirements:

wiring in line with the hand-in-hand approach should be far away from power sources, high-frequency interference sources, heat sources, and corrosive places, especially do not and motor lines, high-power FM equipment, arc welding, pulse radiation robust equipment or lines mixed in parallel and these lines with interference between the distance of at least 5 meters. In addition, the shield should be connected to the earth at one end.

III) Wiring requirements:

Use special crimping tools and waterproof wiring, use high-quality communication industry-certified unique products for wiring, do not use inferior products. Otherwise, it will cause unpredictable faults in data communication transmission.

IV) When wiring, first put the heat-shrinkable tube inside the hose of the remote transmission line, connect the cable, then use the heat-shrinkable tube to protect the waterproof joint.

V) The water meter should be installed according to the instructions on the meter dial or the cover, with the “H” mark for horizontal installation, the meter dial facing upwards, the direction of the case arrow and the direction of the pipe water flow, the upstream of the water meter should be equipped with a control valve to facilitate the removal and maintenance of the water meter. Likewise, the upstream of the water meter should be provided with a control valve to facilitate the removal and maintenance of the meter.

VI) The installation site should be protected from sun and freezing, avoiding pollution and flooding, facilitating disassembly and reading, and taking anti-freezing measures in winter.

VII) Construction should pay attention to protecting hoses and wires, forbidden to tear the hose handling water meter, to avoid hose off or wire sheath rupture.

VIII) The newly installed pipeline should be cleared of debris in the channel first to prevent the water meter from being blocked. Then, when the water meter is installed, pay attention to the connection length of the water meter. When the pipe spacing between the two ends exceeds the connection length of the water meter, is too short, or is not on the same axis, the pipe spacing should be amended; otherwise, the water meter fittings will be damaged or not installed.

IX) Coldwater tables installed in the boiler water inlet end to prevent hot water and steam reflux from the scalding water table.

X) Long-term use of the water table, due to debris in the pipeline, rust, and other blockages, causing changes in error, the user shall not destroy the seal, can be repaired to the water meter testing station.

XI) The specifications are selected according to the flow of the pipe. Therefore, using the flow close to or less than the standard flow is appropriate. It can not determine the water meter’s caliber with the pipe’s caliber.

XII) The water meter is made of dry and wet types. Therefore, water meter glass below the water, water vapor, etc., is a normal phenomenon. However, in use because of old pipes, poor water quality or installed at the end of the pipeline, will cause rust pollution, affecting the reading.

XIII) The upper part of the water meter, that is, the pipeline system should use the least elbow and valve, the water meter should always be filled with water, and make the flow to zero is not less than 0.005Mpa, to avoid the pipeline into the air, if the air may enter the water meter, to prevent “water hammer” fluctuations and water meter reversal, should be installed in the upstream of the water meter bleed valve, to ensure the accuracy of water meter measurement. Ensure the accuracy of water meter measurement.

XIV) When water is not used, if the meter has a small movement due to the unstable pressure of the water flow in the pipeline or due to other reasons, a check valve can be installed at the front of the meter to prevent these situations from occurring and to ensure accurate measurement of the meter.

XV) If the water meter or its accessories are damaged as a result of the installation and use in strict accordance with the installation notes, all losses will be borne by the installer.

7. What are the differences between the Woltman water meter and the rotor water meter？

I.The rotation axis is not in line with the direction of water flow

I)The spiral rotating wing of the Woltman water meter is placed on the rotor, whose rotation axis is parallel to the water flow.

II)The radial rotating wing of the rotary-wing water meter is placed on the rotor whose rotation axis is perpendicular to the water flow.

II.Different appearance

I)The Woltman water meter is like a letter “I” shape road.

2)Rotary water meter looks like a “big belly” water meter.

III.Different uses

1)The Woltman water meter is suitable for use in large diameter pipelines (DN80-DN200), mainly used as an industrial meter.

2)Rotary wing water meter for small diameter pipeline of the total amount of one-way water flow measurement. Such as special caliber 15mm, 20mm specification piped household water consumption measurement.

IV.Different functions

1)Woltman water meter circulation capacity, pressure loss is small, but the measurement accuracy is low.

II)Rotary wing water meter structure is simple, circulation capacity is large, measurement accuracy is high.