Smith 210 series  electro-hydraulic valve is composed by a second open electromagnetic valves, a second closed electromagnetic valves, 2 only 3/8 "manual small ball valve (needle valve) and the main valve ，total  six valve, The usually open valve installed in upstream piping of control circuit , closed electromagnetic valve installed in downstream piping of the control circuit 

The Smith Meter Model AR Air Eliminator separates and release air or gas from petroleum or other liquids before they are passed through the meter ,Complete elimination of air or gas is essential for accurate metering. Therefore,the Smith Meter Model AR eliminator is a necessary part of a metering system when there is a possibility of air or gas being present in the flowstream

The Smith Meter VDR vertical Dearrator will separate and release air and gas from petroleum and other liquid products before they are metered .The deaerator is a necessray part of any metering system .whenever there is a possibility that air or gas can be pumped or siphoned into pipeline