E-7 Electronic Preset Valve with Flow Control Switch (Optional)

Introduction

This manual provides detailed information for the installation, operation, and maintenance of the Liquid Controls E-7 Electronic Preset Valve. It also includes specifications, exploded views, and a bill of materials.

WARNING: Before using this product, read and understand all instructions. Save these instructions for future reference. All work must be performed by qualified personnel trained in the proper application, installation, and maintenance of equipment and/or systems in accordance with all applicable codes and ordinances. Failure to follow these instructions could result in property damage, personal injury, or death from fire and/or explosion, or other hazards associated with this type of equipment.

WARNING: Before disassembly of any meter or accessory component, ALL INTERNAL PRESSURES MUST BE RELIEVED AND ALL LIQUID DRAINED FROM THE SYSTEM IN ACCORDANCE WITH ALL APPLICABLE PROCEDURES. Pressure must be 0 (zero) psi. Close all liquid and vapor lines between the meter and liquid source. Failure to follow this warning could result in property damage, personal injury, or death from fire and/or explosion, or other hazards associated with this type of equipment.

The most current English versions of all Liquid Controls publications are available on their website, www.lcmeter.com. It is the responsibility of the local distributor to provide the most current version of manuals, instructions, and specification sheets in the required language of the country or the end user.

Specifications

General Information

Liquid Controls valves are engineered for a wide range of applications and flow rates, ensuring smooth, accurate, and controlled operation. The E-7 valves are installed on the outlet side of the meter. Their design ensures smooth operation regardless of line pressure, as vector forces are directed at right angles to the valve opening mechanism. The E-7 electronic valve shares mounting dimensions with the V-7 and K-7 mechanical valves, allowing for direct retrofitting without plumbing changes.

Class 2 Valve

A Class 2 E-7 valve is available for aviation applications. It features an anodized aluminum housing and stainless steel tubing, fittings, and solenoid valve parts (Part #A298211A). The Flow Control Switch is not available for Class 2 E-7 Valves.

Flow Control Switch (Optional)

The Flow Control Switch is a bolt-on accessory for the E-7 Valve. It controls an air-operated valve (AOV) connected to the pump. In low flow conditions, the switch is closed (OFF), preventing air to the AOV. In high flow conditions, the switch opens, activating the AOV and switching the pump from low bypass to full flow mode (high bypass). When flow returns to low, the switch closes, venting air from the AOV, which then closes, returning the pump to low bypass mode. The switch can also be routed to the engine throttle to adjust pump shaft RPM and flow. The E-7 valve with Flow Control Switch is compatible with Liquid Controls LectroCount Electronic Registers (M5, M7, M10 Class 1 meters).

Operation

Two-Stage Closure

The E-7 valve uses two solenoids (S1 and S2) for two-stage closure. During full flow, S1 opens and S2 closes. During dwell flow, S1 closes and S2 opens. S2 closing in dwell flow ends deliveries, reducing liquid hammer and ensuring accurate preset deliveries.

Valve Closed

When the E-7 Valve is closed, no delivery is possible. Both S1 and S2 solenoids are de-energized and closed. Fluid enters the inlet, flows through tubing and S1 solenoid into the valve chamber, using fluid pressure and a compression spring to seal the piston against the inlet.

Full Flow

At the start of a delivery, S1 solenoid energizes, opening a port at the back of the valve by raising the piston. Liquid flows through S1 and out the outlet port. This allows inlet pressure to compress the spring, forcing the piston back and opening a path for liquid. S1 remains energized during full flow.

Flow Control Switch Operation

The flow control switch is actuated by the valve piston shaft. When actuated, it allows supply air to pass from the 'IN' port to the 'OUT' port. This 'OUT' air typically routes to the pump's air-operated valve to increase bypass pressure and may also connect to the engine throttle to increase pump shaft RPM and flow.

Note: Air switch ports are shown facing front for instruction purposes only. Recommended orientation is top for condensation drainage.

For LectroCount³, both solenoids energize during full flow.

Dwell Flow

Near the end of a preset delivery, the system transitions from full flow to dwell flow. At this point, S1 de-energizes simultaneously as S2 energizes. After S1 closes, the piston and spring move back, closing the valve path. S2 energizing opens a path for liquid from the front of the valve through the solenoid to the outlet. When the preset volume is reached, S2 closes, ending the delivery.

Flow Control Switch in Dwell Flow

The valve piston de-energizes the internal switch of the flow control switch. The outlet closes, and air pressure vents through the switch's vent port, closing the pump's air-operated valve. If connected to the engine throttle, it reduces pump shaft RPM.

For LectroCount³, S1 de-energizes during dwell flow, and S2 remains energized until the delivery preset is reached.

Installation

New Installations

When ordered with a new meter, the E-7 valve is supplied mounted to the meter's outlet side. Piping connects to the E-7 valve's outlet using provided bolts and washers. The E-7 Valve solenoids are pre-wired to the LectroCount Electronic Register and can be oriented with the outlet facing top, back, forward, or bottom. Air lines connect to the Flow Control Switch via two 1/8" NPT ports; the switch can be rotated in 90° increments for optimal orientation.

Retrofit Installations

After relieving internal pressure and draining the system, disconnect the outlet line from the existing meter or valve. Remove the old valve and connect the new E-7 valve assembly to the positive displacement meter's outlet side.

Tools Required for Installation

• Screwdriver, flat blade
• Screwdriver, Phillips
• Screwdriver, Torx
• 7/16" wrench
• 9/16" wrench

Valve Orientation

The valve has an arrow indicating flow direction and an "OUTLET" marking. The outlet can be positioned in four ways. Solenoid mounting is interchangeable, allowing solenoids to be positioned on either side. Preferred solenoid locations are 'on top' or horizontally facing back or forward. Avoid downward-facing solenoid orientation. Use the four bolts and washers to fasten the valve assembly to the meter, tightening in a crossing pattern. Reconnect outlet piping to the E-7 valve outlet. Wiring instructions are on Page 16.

Flow Control Switch Orientation

Set the flow control switch orientation before filling the system. Remove the four fasteners holding the switch to the E-7 valve, rotate to the desired orientation, and refasten.

Connecting Air Lines

The "IN" and "OUT" air line connections on the flow control switch are 1/8" NPT. Use appropriate fittings and tubing rated for system air pressure. Regulate air pressure between 50 and 150 psi. Connect supply air to the "IN" port. Connect the "OUT" line to the component(s) to be controlled, typically an air-operated valve on the pump and potentially the engine throttle control.

Adjustment

The flow control switch activation value is adjustable from approximately 10 GPM to 45 GPM, depending on the fueling system. Adjusting the switch improves split compartment performance, system wear, and efficiency.

The switch is factory-set to activate at approximately 30 GPM. It deactivates when flow drops below 30 GPM.

To adjust: Loosen the locking screw. To lower activation flow rate, rotate the adjustment screw clockwise. To raise it, rotate counter-clockwise. The total counter-clockwise adjustment should not exceed 2 turns from the lowest setting.

Make small adjustments and test the system to set the desired activation flowrate. Secure the adjustment screw with the locking screw once set.

Adjustments can be made without removing the air supply. If the adjustment screw unthreads beyond 2 turns, shut off air supply before reinstallation.

Dimensional Drawings

E-7 Valve (inches)

Diagrams showing the E-7 Valve from side, top, and front views, with key dimensions labeled (e.g., 2.6", 2.5", 9.5"). Dimensions are not for construction use; consult factory for certified drawings.

E-7 Valve With Flow Control Switch (inches)

Diagrams showing the E-7 Valve with Flow Control Switch from side, top, and front views, with key dimensions and port labels (Inlet, Outlet, 3/8-16 UNC 4 Holes, 1/8-27 NPT 2 Holes) indicated.

Note: Air switch ports shown facing front for instruction purposes only. Recommended orientation is top for condensation drainage.

Installation: Changing Solenoid Orientation

The E-7 valve can be rotated in 90° increments for optimal outlet port orientation. If solenoids are upside down or extend beyond the meter, the solenoid manifold and valve plate can be switched.

Tools Required:

• 9/16" wrench or socket
• Torx screwdriver
• Straight screwdriver
• Phillips screwdriver

Step 1 - Remove the S1 Bypass Tubing

Using a 9/16" wrench, loosen the two fittings on each end of the bypass tubing. Remove the tubing and the fitting from the top of the S1 solenoid.

Step 2 - Remove the S1 and S2 Solenoids

Using a 9/16" wrench, remove the nuts on top of the S1 and S2 solenoids. Lift the solenoid coils off their posts.

Step 3 - Remove the Solenoid Manifold

Using a 7/16" wrench, remove the six screws holding the manifold in place. Remove the manifold. Inspect and replace the four O-rings between the manifold and valve body as needed.

Step 4 - Remove the Valve Plate

Using a 7/16" wrench, remove the six screws holding the valve plate. Remove the plate from the valve body. Inspect and replace the four O-rings as needed.

Step 5 - Re-Mount the Valve Plate

Turn the valve body over. Install the valve plate on the side that originally held the solenoid manifold, ensuring O-ring seals are in place. Align the plate's center holes with the valve body's fastener connections. If alignment is incorrect, rotate the valve plate 180°.

Step 6 - Re-Mount the Solenoid Manifold

Turn the valve body over. Install the solenoid manifold on the side that originally held the valve plate, ensuring O-ring seals are in place. Align the manifold's holes with the valve body's fastener connections. If alignment is incorrect, rotate the manifold 180°.

Step 7 - Reinstall the S1 and S2 Solenoids

Place the solenoid coils over their posts, positioning them for optimal installation and repair. Replace nuts and tighten with a 9/16" wrench. Ensure the solenoid is in the desired orientation before installing bypass tubing, as it cannot be rotated afterward.

Step 8 - Reinstall the Bypass Tubing

Install the bypass tubing without tension, ensuring fittings attach easily. Adjust the elbow fitting on the S1 solenoid if necessary. Tighten fittings with a 9/16" wrench.

Installation: Wiring

WARNING: For North American Installations, comply with the National Electrical Code (US) or Canadian Electrical Code to maintain hazardous location ratings.

Determine the best solenoid orientation before connecting cables to the LectroCount register. Solenoid cable connectors can be rotated in 90° increments for four orientation options. Choose an orientation where the solenoid is not upside down.

Step 1 - Loosen Cable Connector Cover

Using a flat screwdriver, loosen the screw on the cable connector cover.

Step 2 - Remove Cable Connector

Remove the cable connector from the solenoid.

Step 3 - Remove Connector Cover and Screw

Remove the cover and screw from the cable connector.

Note: Markings on the terminal block indicate orientation. The straight slot of the terminal block must align with the male ground post on the solenoid valve, positioned farthest from the valve housing. Rotate and reinsert the terminal block to change orientation.

Step 4 - Remove Terminal Block

Remove the terminal block from the back of the cable connector.

Step 5 - Feed Cable Through Gland

Feed one end of the cable through the cable gland of the cable connector.

Step 6 - Connect Black Wire

Connect the black wire to terminal 2 and tighten with a flat blade screwdriver. Terminals are identified by raised plastic numbers.

Step 7 - Connect Red Wire

Connect the red wire to terminal 1 and tighten with a flat blade screwdriver.

Step 8 - Rotate and Reinsert Terminal Block

Rotate the terminal block to the desired orientation and reinsert it. The straight slot should point to the side of the valve.

Step 9 - Tighten Retention Clamp

Tighten the retention clamp inside the connector housing using a screwdriver.

Step 10 - Tighten Cable Gland

Tighten the cable gland around the cable.

Step 11 - Plug Connector Back In

Plug the connector back into the solenoid. If the cable orientation is incorrect, unplug, remove the terminal block, rotate it, and reinsert.

Step 12 - Place Cover

Place the cover over the cable connector and secure with the screw.

Step 13 - Repeat for Second Connector

Repeat steps 1 through 12 for the second cable connector.

Step 14 - Route Cables to Register

Route cables to the back of the LectroCount register. Refer to Publication Number 500301, "Installation Manual - LectroCount LCR-II Electronic Register" for detailed wiring instructions for the E-7 valve to the LectroCount. A wiring diagram is provided.

Maintenance

Disassembling the Valve

WARNING: Before disassembly, ensure ALL INTERNAL PRESSURES ARE RELIEVED AND ALL LIQUID IS DRAINED FROM THE SYSTEM. Pressure must be 0 psi. Close all liquid and vapor lines between the meter and liquid source. Failure to follow this warning could result in property damage, personal injury, or death from fire and/or explosion, or other hazards.

This section covers complete disassembly. Often, only partial disassembly is needed for maintenance or troubleshooting. Most components can be removed without removing the valve from the meter.

Step 1 - Remove the S1 Bypass Tubing

Using a 9/16" wrench, loosen the two fittings on each end of the bypass tubing. Remove the fitting from the top of the S1 solenoid.

Step 2 - Remove the S1 and S2 Solenoids

Using a 9/16" wrench, remove the nuts on top of the S1 and S2 solenoids. Lift the solenoid coils off their posts.

Step 3 - Remove the S1 Solenoid Guide Post

Remove the plastic bonnet from the base. Remove the two Torx head screws from the solenoid base. Remove the Phillips head screws from the solenoid manifold. Catch the spring and poppet as they slip out. The base and guide post can be removed as a unit if the spring and poppet do not need inspection.

Step 4 - Remove Solenoid S2 Guide Post

Using a Torx screwdriver, remove the four screws holding the guide post. Lift the guide post off the valve. Catch the spring and poppet as they slip out. Remove the diaphragm from the solenoid manifold hole. Be careful not to puncture the diaphragm.

Step 5 - Remove the Solenoid Manifold

Using a 7/16" wrench, remove the six screws holding the solenoid manifold. Remove the manifold.

Step 6 - Solenoid Manifold O-Rings

Inspect and replace the four O-rings between the solenoid manifold and valve body. Inspect and replace the two O-rings at the bottom of the S1 solenoid base. Check and ensure the seal between the S2 solenoid and mounting plate is correctly positioned.

Step 7 - Remove the Cover Plate

Using a 7/16" wrench, remove the six screws holding the cover plate. Remove the plate from the valve body. Inspect and replace the four O-rings on the cover plate as needed.

Step 8 - Remove the Piston Cover Plate

Using a 7/16" wrench, loosen the four screws holding the back end cover plate. Hold the plate down while removing screws. Allow the spring to expand fully before removing the cover. Remove the spring from the valve. Inspect the O-ring on the piston and replace if needed.

Step 9 - Remove the Piston

Lay the valve on its side. Push the piston out from the front end and pull it from the back end of the valve body.

Service Tip: A slight vacuum may form when removing the piston. A long nose pliers can aid removal using the extended fastener for the piston O-ring washer.

Step 10 - Disassemble the Piston

Use a 7/16" wrench to remove the screw holding the piston washer and O-ring. Remove the washer and O-ring. Inspect the O-ring and replace if needed. Check wear rings for excessive wear and replace them. Check the Omni-seal® for wear and replace if necessary.

Reassembling the Valve

Step 1 - Assemble the Piston

Place the O-ring into the piston face groove. Place the piston washer on top of the O-ring and fasten with the screw. Slide the piston into the valve body and press it until it rests against the opposite side.

Step 2 - Replace the Piston Cover Plate

Place the O-ring in the valve housing groove. Insert the spring into the piston center. Place the cover on the spring and compress. Insert the four screws and tighten by hand, then fully with a 7/16" wrench.

Step 3 - Replace the Valve Plate

Select the valve side for the most convenient orientation (inlet, outlet, solenoid location). The valve plate is not symmetrical; its center holes are offset. Ensure correct orientation for proper alignment of all six screws and washers. Insert six screws and washers, tightening with a 7/16" wrench. These screws are the shorter set.

Step 4 - Install the Solenoid Manifold

Install the solenoid manifold in the proper orientation to align porting. Place it on the valve body and insert the six longer screws and washers, tightening with a 7/16" wrench.

Step 5 - Install the S2 Solenoid Post

Replace the diaphragm in the solenoid manifold hole. Assemble the guide post, poppet, and spring. Insert the spring into the poppet top, then push the poppet (spring first) into the guide post. Place the guide post assembly into the diaphragm (poppet first) and start screws. Tighten assembly to the manifold with a Torx screwdriver. Place the plastic bonnet over the metal base.

Step 6 - Install the S1 Solenoid

Place the S1 base onto the manifold with engraved numbers facing opposite the outlet opening. Assemble the poppet and spring into the guide post. The wide end of the spring fits the guide bottom; the narrow end of the poppet faces down and away. Compressing the spring moves the poppet. Place the guide post assembly (poppet first) over the base. Hold to the manifold and start the two long Phillips screws. Tighten the two Torx screws and two Phillips screws. Reattach the plastic bonnet.

Note: The S1 solenoid will NOT operate if oriented incorrectly. Engraved numbers must face the side opposite of the outlet opening.

Step 7 - Install the S1 and S2 Solenoid

Place the solenoid coils over the posts. Replace nuts and tighten with a 9/16" wrench.

Step 8 - Install the Bypass Tubing

Install bypass tubing without tension, ensuring easy fitting attachment. Adjust the elbow fitting on the S1 solenoid if needed. Tighten fittings with a 9/16" wrench.

Torque Chart

*Torque tolerance is ± 10%

Exploded Views and Bill of Materials

Exploded View: A298211 & A298211A (Class 2)

Diagram showing the breakdown of parts for the A298211 and A298211A (Class 2) valve models, with numbered components corresponding to the Bill of Materials.

Bill of Materials: Model Number A298211

Exploded View: A298311 - 501513

Diagram showing the breakdown of parts for the A298311 and 501513 Cover Assembly valve models, with numbered components corresponding to the Bill of Materials.

Bill of Materials: Model Number A298311 / Cover Assembly: 501513