2. How to operate the flowmeter Cable Components Cable Components,Car Transmission Cable,Car Cable Parts,Assembly Cable Qinghe Zhenyuan Auto Cable Factory , https://www.durcables.com
2.1 Corresponding configuration The flowmeter must be equipped with front valve 1, front and rear valve 2 (flow control valve) and control switch valve 3 (also installed behind the flowmeter), see illustration. The front valve 1 and the rear valve 2 may be general mechanical gate valves or ball valves, and the control switch valve 3 may also be a solenoid valve or other valves. (Check valves should be installed after the pump.) 
2.2 Start operation (all valves are closed at this time)
First open the pump - slowly open the front of the valve 1 (to ensure that the flow meter into the oil) - open the control switch valve 3 - finally open the table after the valve 2 is the flow control valve (at this time you can adjust the flow to the desired flow value). At this point, the flow meter starts normal operation.
2.3 Stopping operation is the exact opposite of starting operation. First, close the control switch valve 3 - close the front valve 1 - and finally turn off the oil pump. At this time, it is not necessary to close the regulating flow valve 2 to ensure that the flow still maintains the original constant flow when the next cycle of the flow meter begins to operate.
Warning:
When running for the first time, you must run 50L at a low speed (<60L/min) before accelerating to normal speed, otherwise it is extremely easy to damage the flowmeter.
3, the volumetric flowmeter common fault causes and troubleshooting
2. The measured liquid contains many impurities. The filter is damaged. Impurities enter the table and the gears get stuck. Wash and unpack instruments and pipes and repair filters.  Sealed coupling leaking seal packing wear or lack of seal oil. Tighten the gland or replace the packing and fill it with seal oil.  The pointer rotation is unstable, or the pointer, washer, etc. are moved when stopped, or the rotation of the rotating member is inflexible. Re-tighten to eliminate inflexibility.  The small flow error is too large. The elliptical gears collide with the wall of the metering box, bearing wear, or measurement box wall deformation. Replace the bearing and repair the metering box wall and gears at the variable teeth to make the rotation flexible and ensure the required clearance. After the repair, it is necessary to verify the error change. If the fluid is too large, there is a large pulsation or gas inclusion. Reduce pulsation or install a gas separator  The error is too large, but the difference between the maximum and minimum error does not exceed 1%. The service period is exceeded, or the gap after the inspection changes. Recalibrate and adjust the maximum error of the corresponding 0.2-level flowmeter to no more than 0.4%