... instrument composed by throttling device(orifice plate) of main pipeline and rotary flow meter(glass tube flowmeter,metal tube flowmeter ... graduated tube,it is unnecessary to stop the main pipeline flow(equip with stop valve);This series flow meter ... TypeLZB-()FL series flowmeter are composed by main pipeline,main orifice,shunt pipeline,throttling orifice,rotameter and stop valves (optional).See ...