V cone flowmeter is a new type of differential pressure flowmeter. it avoids the disadvantage of the traditional throttling device and uses the gradual shrinkage throttle method. The working principle is the same as other differential pressure flowmeter and it has the feature of rectifier, self-cleaning and self-protection. The length requirement of the pipe is very short so that there is no contamination or blockage to keep long-term stability. It is widely used in Petroleum, chemicals, electricity, heating etc.