1、 Product Overview:
Hydraulic oil flowmeter is a volumetric measuring instrument used for continuous or intermittent measurement and control of liquid flow in pipelines. It has many advantages such as a large range, high accuracy, low pressure loss, strong viscosity adaptability, ability to measure high-temperature and high viscosity liquids, convenient calibration, and installation suggestions. Suitable for flow measurement in departments such as petroleum, chemical, synthetic fiber, transportation, commerce, food, medicine and health.
OW-LC hydraulic oil flow meter is a lightweight volumetric flow instrument with pointer display, word wheel cumulative counting device, and zero return device. It is widely used in liquid flow control in various industrial fields and is suitable for measuring various types of liquids, such as crude oil, diesel, gasoline, etc. The instrument has high accuracy, large range, high precision, and convenient use and maintenance. Less affected by changes in liquid viscosity and pressure. By selecting different manufacturing materials, liquid flow measurement can be achieved in various fields such as petroleum, chemical, pharmaceutical, food, metallurgy, electricity, and transportation.
2、 Principle and structure of hydraulic oil flowmeter:

The liquid flow rate is measured indoors
There is a pair of elliptical gears in the measuring room. Under the pressure difference between the liquid at the inlet and outlet, the elliptical gears rotate continuously on the shaft. The total amount of liquid flowing through the instrument can be determined by measuring their number of revolutions.
As shown in Figure 1 (a), a pair of elliptical gears A and B separate the inlet and outlet, forming a crescent shaped space between gear A and the inner wall of the measuring chamber. Gear A has a rotational torque, while gear B has a total torque equal to zero,
Gear A drives gear B to rotate. Figure 1 (b) shows the middle position of the two wheels. When rotated to position (c), gear A loses its transmission torque, while gear B gains rotational torque. Gear B drives gear A to rotate, as shown in (d). The angle of rotation of an elliptical gear is non-uniform.
A pair of elliptical gears rotate once, accumulating four times the volume of the crescent space. The rotation of the elliptical gears is transmitted through the transmission wheel system to the pointer and letter wheel of the calculation mechanism, which determines the total amount of liquid flowing through the instrument.
◆ Structure
1. Measurement part: The ordinary instrument housing is made of cast iron, and its inner cavity forms the measurement chamber. There are two stainless steel shafts in the measurement chamber, and a pair of elliptical gears are sleeved on the shafts to rotate. The gap between the elliptical gears and the inner wall of the measurement chamber is very small, only a few tens of microns, to reduce the leakage of the instrument.
2. Transmission integration part: The instrument transmission wheel system and integration mechanism record the flow rate value of the elliptical gear rotation speed, and the total amount of liquid flowing through the instrument is represented by pointers and character wheels.
3. Sealing structure: The measuring chamber of the shaft sealing instrument is sealed, and the transmission source of gear rotation is sealed with polytetrafluoroethylene as packing. This method is structurally simpler. The measuring chamber of the magnetic steel sealed instrument is sealed, and the transmission of the elliptical gear is transmitted to the counter through the active permanent magnet and the passive permanent magnet. The sealing structure between the active permanent magnet and the passive permanent magnet is composed of a coupling and a sealing gasket, which is safe and reliable.
4. Materials that come into contact with liquids include cast iron, cast aluminum, stainless steel, carbon steel, brass, tin phosphor bronze, oil resistant asbestos rubber sheets, and polytetrafluoroethylene fillers.
◆ Parameters:

3、 Installation and use of hydraulic oil flow meter:
1. The installation direction should be such that the arrow direction on the instrument housing is the same as the liquid direction, and the installation position should be convenient for reading.
2. Try to install it at room temperature, and do not install it in environments with harmful gases or strong thermal radiation, which may cause damage to the instrument counter.
3. The elliptical gear should be installed in a horizontal position as much as possible, that is, the dial should be installed in a vertical position (the division "0" should be on top),
To reduce the friction between the two planes of the elliptical gear and the housing, and to minimize component wear.
4. Installed at the output end of the pump, if installed at the suction end, the pressure loss of the instrument filter increases the negative suction pressure of the pump, and the liquid outflow at the pump shaft also increases the error of the instrument. The flange at the suction end of the pump should also prevent air leakage, otherwise it will also increase the error of the instrument.
5. A filter should be installed in front of the flowmeter to prevent particles larger than 0.2 millimeters from passing through and to prevent blockage of the instrument due to particles. The filter should be easy to clean.
6. It is best to install a check valve in front of the flowmeter to ensure that the liquid in the pipeline can only flow in one direction and prevent damage to the counter.
7. Suggest setting up bypass and valves as shown in the figure, which can be installed horizontally, vertically or in other directions from top to top, from top to bottom, from left to right, and from right to left.

8. When in use, the meter should be filled with liquid and there should be no gas mixed in the measured liquid, otherwise the measurement may be inaccurate. Liquid mixed with gas must be equipped with a gas separator in front of the instrument.
9. Before installation, the pipeline in front of the meter should be carefully cleaned of debris. Only when the instrument is connected to the pipeline can the sealing plug on the instrument interface be removed to prevent debris from entering the meter. When installing instruments, precautions should be taken to prevent debris from falling into the pipeline.
10. When the flow rate exceeds the specified maximum flow rate, the wear of the elliptical gear increases with the increase of the rotation speed, and the pressure loss increases sharply. Therefore, it should be avoided from use. Although it can still be calculated below the minimum flow rate, the error increases. When the liquid viscosity is 10 centipoise, the starting flow rate of the instrument is about 1% of the full range.
11. Each instrument is calibrated with a No. 7 mechanical oil gauge at room temperature before leaving the factory, and the viscosity of the oil varies with room temperature, with a viscosity of 13 centipedes per month at room temperature. In theory, the change in liquid viscosity measured by a volumetric flowmeter does not affect the measurement accuracy. However, in reality, due to the gap between the measuring chamber wall and the elliptical gear, the amount of leakage generated in the gap is affected by the viscosity of the liquid.
12. When used to measure highly viscous liquids, the liquid is generally heated to reduce viscosity, and then circulated in the pipeline. When the instrument is stopped, the liquid filled in the instrument cools down and becomes viscous. If it is to be activated, it is necessary to use steam to heat the liquid outside the title, and only use it after the viscosity of the liquid inside the instrument has decreased. Otherwise, the mucus will hold onto the transmission parts and cause damage. It is strictly prohibited to sweep steam through the meter body to avoid damaging the instrument.
13. The temperature of the tested liquid should not exceed the specified value. If exceeded, it may even get stuck and cause additional errors in viscosity due to changes in liquid temperature. In addition, the increase in temperature also causes an increase in the volume of the crescent space, which slows down the instrument. When the measuring chamber and elliptical gear are made of cast iron, the additional error is about+0.33%/100 ℃; The measuring room is made of cast iron, and if the elliptical gear is made of cast aluminum, the additional error is+0.14%/100 ℃.
14. The flow rate in the pipeline should not increase or decrease dramatically in an emergency, and pipeline vibration, hydraulic shock, and rapid pressure fluctuations should be avoided, otherwise it will affect the normal operation of the instrument.
15. The pressure loss is proportional to the square of the liquid flow rate, and as the viscosity of the liquid increases, the pressure loss also increases.
4、 Storage, packaging, and transportation of hydraulic oil flow meters:
1. The flowmeter should be stored in a dry room and have a dedicated packaging box to prevent damage to the instrument.
2. When packing the instrument, the dial should be placed on top and securely fixed inside the wooden box to prevent the instrument from moving and being damaged during transportation. There should be indelible markings on the packaging box, such as "up" or "", "precision instrument" or "symbol", "handle with care", etc.
3. During transportation, it should be done after packing and avoid impact and severe vibration.
4. Before installation, the inlet and outlet should still be sealed to prevent debris from entering the instrument.
5、 Ordering and Repair of Hydraulic Oil Flow Meter:
1. When ordering instruments, it is necessary to specify requirements such as model, name, specifications, measurement range, nominal pressure, working temperature, and the name of the measured liquid.
2. Within 12 months after the instrument is shipped from the factory, if the user fully complies with the product technical requirements and the transportation, storage, installation, and use regulations specified in the user manual and finds that the instrument does not meet the product technical standards, the instrument can be returned to the factory for repair or replacement.
3. When repairing an instrument, it is necessary to specify in detail the environmental conditions, measurement object, usage time, and fault symptoms of the actual installation location of the instrument, as well as the contact person, location, original voucher number, date, etc. of the place where the repair will be shipped.
Hydraulic oil flow meter return to zero flow meter:

1. Accumulated counter; 2. Return to zero counter; 3. Pointer reset handle; 4. Counter reset handle; 5. The pointer zeroing counter is a newly developed product by our factory, with a large character code, clear indication, convenient and reliable, and long service life. The counter is equipped with two sets of character wheels for zeroing and accumulating, and has dual functions of batch counting and total accumulation. When in use, rotate the handwheel handle clockwise to return the zero counter digit group to zero position; Pinch the handle inward and rotate clockwise to return the pointer to zero position (counterclockwise rotation of the pointer).