Liquid Controls Optical Vapor Eliminator

Introduction

General Information

The Liquid Controls Optical Vapor Eliminator (A8302) is designed for use with LectroCount® electronic registers and requires a solenoid-operated valve. It is constructed for use with Liquid Controls MA5 and MA7 meters measuring liquid propane gas (LPG). Its mounting dimensions are compatible with Liquid Controls mechanical vapor eliminators, minimizing plumbing changes for retrofits. Electronic registers require CPU board part number 81920 for LCR and LCR-II, or CPU board part number 81924 for LC³.

NOTICE: A8302 LPG metering systems use materials specifically intended for their application to ensure high performance, longevity, and safety. Do not use a system designed for LPG to deliver another product without replacing necessary metallurgical and seal materials. Conversion kits are available from Liquid Controls.

How the Optical Vapor Eliminator Works

The Optical Vapor Eliminator removes vapor from the metering system, ensuring only liquid is measured. An optical sensor within the housing activates and deactivates a solenoid valve (S3). When the liquid level is below the optical sensor during a delivery, the solenoid valve opens to vent vapor to a supply or storage tank. Simultaneously, the electronically actuated control valve at the meter outlet closes, stopping product flow.

As vapor is vented and liquid rises to cover the optical sensor, the solenoid valve (S3) closes the vent, and the outlet control valve opens, allowing delivery to begin or continue. The solenoid valve remains closed and the outlet valve open as long as the liquid level is at or above the sensor. If the liquid level drops below the sensor, the solenoid valve opens to vent vapor, and the outlet valve closes, blocking product flow. Upon completion of a delivery, both valves close until the next activation.

Figure 1: Liquid Level below Optical Sensor: Depicts the optical sensor below the liquid level. The solenoid valve is shown open, venting vapor, while the outlet valve is closed. The LectroCount® register is shown displaying measurements.

Figure 2: Liquid Level at or above Optical Sensor: Shows the optical sensor covered by liquid. The solenoid valve is closed, and the outlet valve is open, allowing product flow. The LectroCount® register is shown displaying measurements.

The figures below illustrate the vent port through the solenoid valve:

Figure 4: Solenoid and Port Open: A cutaway view showing the S3 solenoid valve open, allowing air/vapor to pass through the vent port.

Figure 5: Solenoid and Port Closed: A cutaway view showing the S3 solenoid valve closed, blocking the vent path.

Figure 6: Optical Vapor Eliminator Operating Sequence: This diagram outlines the operational logic for a preset delivery, detailing the states of the Optical Vapor Eliminator (Solenoid 3) and the meter outlet valve (Solenoid 1) based on liquid level and delivery stage (e.g., Initiate Delivery, End of Delivery, Two-Stage Valve operation).

Specifications

Optical Vapor Eliminators (A8302)

Safety Procedures

! 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 equipment.

Be Prepared

In the Event of a Gas Fire

In the event of large fires or fires that are spreading:

• Evacuate the building and notify your local fire department.
• Stop the leakage only if you can safely reach the equipment.

In the event of small, contained fires that you can safely control:

• Stop the leakage if you can safely reach the equipment.
• Use the appropriate extinguisher: Class B fire extinguisher, water, fog, etc., depending on the materials.
• If in doubt, call your local fire department.

In the Event of a Gas Leak

In the event of a large gas leak:

• Evacuate the area and notify the fire department.

In the event of a small, contained gas leak:

• Stop the leak and prevent accidental ignition.
• Prevent the entrance of gas into other portions of the buildings. Some gases, such as LPG, seek lower levels, while other gases seek higher levels.
• Evacuate all people from the danger zone.
• See that the gas is dispersed before resuming business and operating motors.
• If in doubt, notify your local fire department.

Publication Updates and Translations

The most current English versions of all Liquid Controls publications are available on their website, www.lcmeter.com. Local distributors are responsible for providing current versions in the required language. Contact your local distributor for language-related questions.

Installation

Dimensional Drawing

Diagrams on page 7: These diagrams show the top, side, and rear views of the Optical Vapor Eliminator with key dimensions indicated. Note: Dimensions shown are not for construction use; consult the factory for certified engineering drawings.

New Installations

When ordered with a new meter, the optical vapor eliminator is supplied mounted on top of a strainer on the inlet side of the meter.

Figure 7: New Assembly: Illustrates the optical vapor eliminator mounted on the meter's inlet strainer.

A vent line must be connected from the output port of the optical vapor eliminator to a supply or storage tank. This connection is 1½" NPT. The vent line must be connected to the supply or storage tank.

The optical vapor eliminator solenoid valve and optical sensor are shipped pre-wired to the LectroCount® electronic register.

Retrofit Installations

Adding an optical vapor eliminator may require modification of vent piping, the outlet valve, and the register, depending on the existing configuration. Refer to the manuals for these components for proper installation and configuration.

Figure 8: Remove old Vapor Eliminator: Shows the process of removing the existing vapor eliminator.

Figure 9: Orient and Fasten the Optical Vapor Eliminator: Depicts orienting and securing the new optical vapor eliminator to the strainer.

To retrofit an optical vapor eliminator:

1. Remove Old Vapor Eliminator and Baffel Cup: After relieving internal pressure and draining liquid, remove the four bolts and washers securing the vapor eliminator. Inspect and replace the O-ring if necessary.
2. Mount the Optical Vapor Eliminator: Depending on the strainer used, the eliminator can be fastened in four 90° rotational increments. Select the best orientation for wiring and vent piping. Fasten using the four bolts and washers, tightening to 27 lb-ft (37 Nm).
3. Connect the Control Piping/Tubing for LPG: Make plumbing connections from the 3-way solenoid valve assembly to the vapor eliminator and differential valve assembly, following the lettered designations shown in Figure 10.
4. Wire the Solenoid and Sensor to the Register: Wiring instructions are provided on page 10.

Figure 10: LPG Plumbing Connections: Illustrates the plumbing connections for LPG systems, showing the routing from the solenoid valve assembly to the vapor eliminator and differential valve.

Figure 11: Optical Sensor and Solenoid Valve: Shows the connection points for the optical sensor and solenoid valve.

Relieving Internal Pressure

! WARNING

All internal pressure must be relieved to zero pressure before disassembly or inspection of the strainer, vapor eliminator, valves, packing gland, or covers. Failure to do so could result in serious injury or death from fire or explosion.

Relieving Internal Pressure Procedure for LPG and NH3 Meters:

1. Close the belly valve of the supply tank.
2. Close the valve on the vapor return line.
3. Close the manual valve on the supply line inlet side of the meter. If none exists, consult the truck manufacturer.
4. Slowly open the valve/nozzle at the end of the supply line.
5. After product has bled off, close the valve/nozzle at the end of the supply line.
6. Slowly crack the fitting on top of the differential valve to relieve system pressure. Product will drain.
7. As product drains, slowly reopen and close the valve/nozzle on the discharge line. Repeat until product stops draining.
8. Leave the discharge line valve/nozzle open while working on the system.

Wiring

The electrical installation involves connecting the S3 solenoid and optical sensor to the LectroCount register.

The optical sensor has a 24" cable potted at one end and a threaded cord grip at the other for connection to the register.

The S3 solenoid-operated valve requires a 12 AWG, two-wire, braided cable (approx. 24-36" long).

The S3 solenoid requires a LectroCount® LCR/LCR-II register with CPU board 81920 or 84040 (LC³ with 81924). Replacement CPU boards are available if needed. The 81920/84040 CPU board has an additional terminal, J15 (J11 on LC³ 81924), vital for the optical vapor eliminator.

To wire the S3 solenoid and optical sensor:

1. Remove Cable Plug: Loosen the screw on the S3 solenoid valve cable plug cover, remove the plug from the coil, and remove the terminal block. Note its orientation. Leave the gasket on the coil.
2. Connect Cable to Cable Plug: Route the cable through the conduit fitting into the plug housing. Connect wires to the terminal block: BLACK wire to Terminal 2, RED wire to Terminal 1. Terminals are marked "1" and "2".

! Caution: Incorrect wiring can damage the optical sensor and the LectroCount® register.

! WARNING: For North American installations, comply with the National Electrical Code (US) or Canadian Electrical Code.

Diagrams on pages 10-11: These illustrate the wiring connections for both LC³ and LCR registers. They detail the optical sensor and S3 solenoid connections, including wire colors, terminal numbers, and CPU board pin assignments (J11 for LC³ and J15 for LCR).

LC³ Wiring:

• Optical Sensor Connection: Red to J11 Pin 33, White to J11 Pin 34, Black to J11 Pin 35.
• S3 Solenoid Connection: Terminal 1 (Red) to J11 Pin 31, Terminal 2 (Black) to J11 Pin 32.

LCR Wiring:

• Optical Sensor Connection: Red to J15 Pin 56, White to J15 Pin 55, Black to J15 Pin 54.
• S3 Solenoid Connection: Terminal 1 (Red) to J15 Pin 52, Terminal 2 (Black) to J15 Pin 53.

3. Reassemble Cable Plug: Reinstall the terminal block, tighten the strain relief strap, and secure the cable gland. Reconnect the plug to the coil and fasten the cover with the screw (torque to 8.8 in-lbs / 1 Nm).

4. Connect to LectroCount® Electronic Register: Route cables to the back of the register and connect them to the appropriate open ports.

Maintenance

! WARNING: Before disassembly, all internal pressures must be relieved and the system drained. Failure to do so can result in serious injury or death from fire or explosion.

Disassembly

The optical vapor eliminator consists of a housing, optical sensor, and solenoid-operated control valve. Only the solenoid valve is serviceable. If any part of the solenoid is damaged, a new solenoid assembly (PN 502011) can be ordered. The optical sensor has potted internal components and must be replaced as a complete assembly (PN 81947) if it fails.

Tools required: Flat blade screwdriver, 14 mm box end or open end wrench.

To disassemble the S3 solenoid:

1. Loosen the thin hex nut holding the solenoid in place with a 14 mm wrench. Remove the nut and coil from the armature guide post.
2. Remove the plastic bonnet from the armature guide post.
3. Using a screwdriver, loosen the upper left and lower right screws of the valve body. These screws hold the valve body in place. The upper right and lower left screws fasten the armature guide post and valve body together. Remove the valve body from the housing.
4. Place the valve body on a flat surface. Remove the two screws holding the armature guide post and valve body together. Lift the armature guide post off. Inspect the plunger and spring inside for damage.

Diagrams on page 12: These illustrate the steps for disassembling the S3 solenoid, showing the removal of the coil, bonnet, valve body, and armature guide post.

Component Inspection:

• Armature Guide Post: Composed of two O-rings, the guide post, and the flange. Inspect for damage.
• Valve Body: Has two identical O-rings on the face that mates with the housing. Inspect O-rings and ports for blockage.

Reassembly

1. Place the spring inside the plunger and insert the plunger (spring end first) into the armature guide post. Place the armature guide post assembly onto the valve body. Fasten the armature guide post to the valve body using the appropriate screws (two holes are threaded, two are not).
2. Align the solenoid valve body so the stamped number faces inward towards the housing assembly. Fasten the valve body to the housing, tightening to 15-18 in-lbs (1.7-2.0 Nm). IMPORTANT: If the stamped numbers face away from the housing, the optical vapor eliminator will not function properly.
3. Place the plastic bonnet over the valve body and snap it into place.
4. Place the coil over the armature guide post and fasten with the thin hex nut. Tighten with a 14mm wrench to 4.5 in-lbs (0.5 Nm).

Diagrams on page 13: These illustrate the reassembly steps for the S3 solenoid, including placing the spring and plunger, aligning the valve body, and securing the coil.

Optical Sensor Replacement

! WARNING: Before disassembly, all internal pressures must be relieved and the system drained.

To replace the optical sensor (PN 81947):

1. Drain the system and relieve all internal pressures.
2. Use a 1" open end wrench to remove the optical sensor from the housing.
3. Replace with a new optical sensor. Tighten to a maximum torque of 75 in-lbs (8.5 Nm). Apply a light coating of grease or anti-seize lubricant to the sensor threads before assembly.

Troubleshooting

Excessive liquid flowing out of vent to supply or storage tank.

• Scenario 1: Solenoid not closing.
• Check S3 solenoid wiring.
• Measure S3 solenoid resistance (should be approx. 15 Ω). Replace if incorrect.
• Inspect S3 solenoid for blockage (refer to disassembly instructions).
• Check for LectroCount® CPU failure; replace CPU board if necessary.
• Scenario 2: Optical sensor not functioning.
• Check optical sensor wiring.
• Measure resistance between RED and WHITE wires (should be approx. 10 kΩ). Replace if incorrect.
• Check for LectroCount® CPU failure; replace CPU board if necessary.

Liquid not flowing though meter during delivery.

• Scenario 1: Liquid level not rising in optical vapor eliminator.
• Check if S3 solenoid is opening to allow air/vapor to vent.
• Check S3 solenoid wiring.
• Measure S3 solenoid resistance (should be approx. 15 Ω). Replace if incorrect.
• Inspect S3 solenoid for blockage (refer to disassembly instructions).
• Check for LectroCount® CPU failure; replace CPU board if necessary.
• Scenario 2: Meter outlet valve not opening.
• Check wiring of the outlet valve S1 solenoid.
• Measure S1 solenoid resistance (should be approx. 15 Ω). Replace if incorrect.
• Inspect S1 solenoid for blockage (refer to valve manual).
• Check for LectroCount® CPU failure; replace CPU board if necessary.

Bill of Materials - Exploded View

Page 15: This page provides an exploded view diagram of the A8302 Optical Vapor Eliminator (LPG), listing all components with their part numbers and descriptions. Key parts include the Air Eliminator Housing (501520), 2-Way Solenoid Valve (502011), Liquid Level Sensor (81947), and various connectors, screws, and fittings.