The three most common Liquid Controls meter systems with two stage valves are:
•a block valve with a S1 and a S2 solenoid-operated valve fitted onto external piping (A2848-11)
•a block valve with a S2 solenoid-operated valve (A2859-11) and a 3-way solenoid on the LCR 600
•and an E-7 valve with a S1 and a S2 solenoid-operated valve
A2848-11 Valve
This two stage control valve has a S1 and a S2 solenoid operated valve. The S1 solenoid-operated valve is located at the meeting point of three bypass pipes: one pipe from the inlet side of the valve, one from the top of the block valve, and one from the outlet side of the valve. The S2 solenoid valve is located on a bypass pipe that connects the inlet and outlet sides of the control valve. It opens while the control valve is closed to supply the dwell flow. This valve is typically used in refined fuels applications.
A2859-11 Valve and 3-Way Solenoid
A two- stage valve with a S2 solenoid-operated valve and a 3-way solenoid valve attached to the back of the LectroCount LCR 600. The 3-way solenoid-operated valve is located at the meeting point of two pipes from the vapor eliminator (one for eliminated vapor and one leading to the spit tank) and one pipe to the top of the block valve. The S2 solenoid valve is located on a bypass pipe that connects the inlet and outlet sides of the control valve. It opens while the control valve is closed to supply the dwell flow. This configuration is typically specified for products that hold vapor in the line such as LPG and NH3.
E-7 Valves
A two stage valve with a S1 and a S2 solenoid-operated valve. The E-7 valve is fitted with one external pipe to divert product flow to the closing mechanism. To supply a dwell flow, the E-7 redirects the product around the closed valve using channels molded into its housing. This valve is typically used in refined fuels applications.
