... structure 2.sensitivity adjustment,easy installation 3.adjustable valve is optional 4.DN3,4,6,10 ... variable area flowmeter is equipped with a needle valve in the base to facilitate precise setting of ... rates,LZB-()W series flow meters without needle valve.On request, these valves can also be ... :vicky_china68Website:www.qf-meter.com flowmeter with valve,sight glass flow meter,micro flow rate ...