LZS plastic tube float flowmeter selection

Project Overview

The main components such as the plastic tube float flow meter cone tube are made of AS and ABS plastics, which have good corrosion resistance. The product also has the characteristics of reasonable structure, small size, light weight, and the cone tube is not easy to break. Widely used in chemical, environmental protection, food and other industrial sectors. Features and description of LZS- series plastic tube flowmeters. There are two types of LZS series flowmeters, which are divided into long tube type and short tube type. It adopts plastic shell and is resistant to 30% acid and alkali corrosion.

The main measuring element of the plastic tube float flowmeter is a tapered plastic tube installed vertically with the small end downward and the large end upward, and a float that can move up and down inside. When the fluid flows through the tapered plastic tube from bottom to top, a pressure difference is generated between the upper and lower floats, and the float rises under the action of this differential pressure. When the force that causes the float to rise is equal to the combined force of gravity, buoyancy and viscosity, the float is in an equilibrium position. Therefore, there is a certain proportional relationship between the fluid flow rate flowing through the flow meter and the rising height of the float, that is, the flow area of ​​the flow meter. The position height of the float can be used as a flow measurement. Principle: The flow detection element of the float flowmeter is composed of a vertical tapered tube that expands from bottom to top and a float group that moves up and down along the axis of the tapered tube. Working principle: When the fluid to be measured passes through the annular gap 3 formed by the cone tube 1 and the float 2 from bottom to top, a differential pressure is generated at the upper and lower ends of the float to form a rising force of the float. When the rising force on the float is greater than the weight of the float immersed in the fluid, The float rises, the annulus area increases, the fluid flow velocity in the annulus immediately drops, the differential pressure between the upper and lower ends of the float decreases, and the lifting force acting on the float also decreases until the lifting force is equal to the weight of the float immersed in the fluid. The float is stable at a certain height. There is a corresponding relationship between the height of the float in the tapered tube and the flow rate passing through it. 2. Introduction to the transparent conical tube float flowmeter with a diameter of 15-40mm.

3. LZS- series plastic tube flowmeter structure diagram and dimensions

4. Remarks: 1). Working pressure :≤0.6MPa2). Working temperature: 0~60 C3). Accuracy: ±4%4). Material: tapered tube: AS; guide rod: stainless steel 304; joint: ABS5). Plastic tube flowmeter can be made into flange Connection type or pipe thread connection type 6). The float, pipe joints, guide rods and other materials can be customized according to customer needs.

〔1〕Before installation, the foam support in the instrument should be removed with a tool tip Use pliers to gently remove it, and then reinstall it. When installing, pay attention to whether the rubber gasket is installed in the groove of the pipe to prevent water leakage.

〔2〕The interface of the flow meter can be connected with matching ABS plastic pipes or PVC plastic pipes, bonded with special glue, or connected with the plastic method and then connected to the metal flange.

〔3〕The flow meter must be installed vertically without obvious inclination. The installation height should be convenient for reading the float. When reading, the line of sight and the float should be horizontal. [General standard: The optimal flow rate required is 50%-70% of the maximum flow rate of the flow meter. Try not to use the highest number.

〔4〕There should be a straight pipe section 5 times the diameter of the instrument at the upstream and downstream inlets and outlets of the instrument.

〔5〕The pressure of the fluid on the side must be stable. If the fluid is too unstable, it will cause the float to fluctuate and prevent correct measurement. A buffer or setter should be installed upstream of the flow meter.

〔6〕The flow meter should be installed vertically, and the angle between the center line of the flow meter and the plumb line should not exceed 5 degrees.

Usage:

〔1〕When using the instrument, you should first slowly open the upstream valve to fully open, and then use the regulating valve downstream of the flow meter to adjust the flow. When the instrument is stopped, the upstream valve should be slowly closed first, and then the flow regulating valve downstream of the instrument should be closed.

〔2〕The indication value of the meter can be seen in the middle of the engraved line, and the value can be read from the scale of the float according to the height of the rise of the float.

〔3〕When the cone tube and float are stained, they should be cleaned in time.

〔4〕Regularly check the error of the flow meter. Once the specified error is exceeded, the float and cone should be replaced, or recalibrated to obtain better accuracy.

〔5〕When the measured fluid is different from the flow meter calibration medium, the indication value needs to be corrected. Expressed by the following formula.

QS=QN

QS=actual flow Qn=flow meter reading value

ρn=medium density ρs= when calibrating the flow meter The density of the measured medium ρf = the density of the float material.