EnglishThe main measuring elements of the glass rotor flowmeter are a vertically installed lower small and upper large conical glass tube and a float that can move up and down.
Generally speaking, in flow measuring instruments, except for positive displacement instruments, which do not have too many requirements for the fluid state, other instruments generally require the fluid to be as stable as possible (laminar flow state), so that the measurement results can be more accurate and stable. . Therefore, try to keep a long enough straight pipe section on the upstream side of the flowmeter (straight pipe section refers to the pipe with the same diameter as the flowmeter, and cannot contain elbows, tees, valves, etc.). If there are valves, they are generally installed in The downstream of the flowmeter, so as not to have an impact on the measurement of the flowmeter (the most direct impact is the large fluctuation of the display value of the meter), if it must be installed upstream, the valve should be fully opened as far as possible to eliminate the influence on the flowmeter measurement to the greatest extent.
The selection of glass rotor flowmeter can be considered from the following aspects.
1. The object to be measured. That is to measure the type of medium, pressure, and chemical properties. Such as liquid medium, gas medium, corrosion-resistant flowmeter should be selected for corrosive medium.
2. The performance of the flow meter itself. After the above conditions are determined, generally speaking, if there is no major change in the price, the needle valve placed on the upper part of the flowmeter is preferred; the one with a larger flow hole is a direct flow scale; the structure is simple; the outer size is smaller, etc. . If it is a small flow range, you can choose the ball float type, because it is stable in measurement, not easy to accumulate dust, high accuracy, and good interchangeability.
3. Choose according to price. Generally speaking, the price with high precision is high. The accuracy level of the instrument should be selected according to the measurement purpose. For example, if only the throughput of the measurement medium needs to be controlled, and the throughput must be stabilized after trial operation and adjustment, then the accuracy is secondary.
