LOKRING TUBING CONNECTORS A HIGHLY RELIABLE METHOD FOR JOINING METALLIC TUBING
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LOKRING HISTORY In the late 1960’s, LOKRINGs were invented to solve braze joint problems in the B-1 bomber program. By the late 1970’s, the patent rights for refrigerant applications were secured by the VULKAN-Hackforth Group in Germany. VULKAN LOKRING was integrated into the VULKAN Hackforth Group and design, manufacturing and sales were launched in 1979. Due to the extensive use of ISO-Butane, LOKRINGs quickly dominated the OEM and service markets in Europe. In 1992, VULKAN-Hackforth purchased rights to the US market. More than 90 Million OEM rings are being installed annually by Appliance, HVAC & Automotive manufacturers.
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Speed and Ease of Installation The LOKRING Tube Connection allows a fast and reliable connection of tubes, even of different material. This tube connection system is a cold, clean method that eliminates brazing, burn permits, damage due to flame, and the need for nitrogen flow during installs. Reports from the field indicate Labor savings of between 30% and 50% on various Ductless System Installations. 3
The Simple Steps To Making LOKRING Connections
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Tube Ends •
Tubing should be cut using a wheel type cutter equipped with sharp wheels.
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Ream all cut tube ends to the full inside diameter of the tube to remove the small burr created by the cutting operation.
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If this rough, inside edge is not removed by reaming, erosion & corrosion may occur due to local turbulence and increased local flow velocity in the tube. Noise, sounds like water running and pressure drop can occur at this point
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Tube Cleaning
Tubes should be cleaned using a radial motion with an abrasive mat or similar fine abrasive product.
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Stabilization Inserts
Stabilization Inserts should always be used on copper tube sizes 3/8 inch thru 1 3/8 inch, as the insert not only gives stability but increases the pull out strength of the connector. 7
Visual Aid for Proper Tube Insertion 1.
Remove ring from LOKRING body.
2.
Place ring over tube chamfered side toward tube end.
3.
Place Stabilization Insert in tube and then the LOKRING body over tube end until fully seat against internal stop and mark tube. Then remove LOKRING body and apply required dosage of Lokprep.
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4.
After completing connection, marks aligning with LOKRING body end indicate tube is correctly inserted.
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Lokprep Lokprep is an anaerobic sealer used to fill leak paths created by small imperfections, scratches, & extrusion lines that are present on all manufactured tubing and is a very important part of the LOKRING process. Lokprep is designed to stay semi pliable and thermal cycle with the tubing between temperature extremes of -58 F to 302 F. Temperatures above 302F may burn out the Lokprep and cause leaks. Such as a torch too close to the connector!
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Lokprep Application The correct dose of Lokprep is enough to create a thin layer over the complete exterior of the tube that comes in contact with the inside of the LOKRING connector.
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Dispersing Lokprep The LOKRING should be placed over the end of the tube and turned 360 degrees to evenly disperse Lokprep. Once Lokprep is applied the connection should be completed within 4 minutes. 11
Wrong
Tube must be inserted fully to LOKRING internal stop.
Correct
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LOKRING Assembly Tool
Position the tool with the correct jaws sizes over the LOKRING connector as shown and operate the tool ensuring the tube remains fully inserted and jaws are properly seated.
Continue to operate the tool until the ring is fully seated against the stop. Use the same steps to complete the other side of the LOKRING connector.
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Completed Connection
Both rings fully seated against stops. LOKRING connection is ready for service.
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Allow Lokprep a minimum of 10 minutes set up time before applying radial torque, stress, vacuum or pressure to the connection. (Note in temperatures below 55 F allow 30 minutes)
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EURO FLARE CONNECTION R410A LOKRING Euro Flares are available in sizes ¼ inch thru ¾ inch. These connections are used at Outdoor Units, Branch Selector Boxes, and Indoor Units. Mechanical connections should always be made 1st, then the LOKRING connector ! 16
R410A Euro Flares take the Failure Modes Out!
R410A systems require exacting flare specifications and forming procedures. These specs are different than standard 45 degree SAE flares. Failure to follow manufacture’s specs on flare connections is the Number 1 cause of System Leaks
Lokring Euro Flares include replaceable preformed flare inserts, nut and Lokring connector half body, and are designed for use on R410A system.
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Installing a Lokring R410A Euro Flare No joint compound or sealer should be applied to mating surfaces of flare faces. Threaded connection should be tightened to manufactures specs before completing Lokring connection. A new flare insert should be used each time the connection is loosened or taken apart for service. A drop of oil compatible with the system oil should be applied to the seal and back of the flare body to ensure accurate torque reading.
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LOKRING Basics Recap 1. 2. 3. 4.
5. 6. 7.
Clean tube ends with abrasive mat or fine emery cloth & deburr as necessary. Install stabilization inserts for 3/8� thru 1 3/8� tube. Place the ring (chamfered edge facing tube end) over the tube if not pre-mounted on the LOKRING body. Apply sufficient Lokprep to create a thin layer over the complete exterior of the tube that comes in contact with the inside the LOKRING connector. Place LOKRING over tube to internal stop and rotate tube or LOKRING to distribute Lokprep. Using appropriate jaws and LOKRING assembly tool, push the 1st ring onto the LOKRING body until fully seated to stop. Repeat steps 3 thru 6 for second side of LOKRING connector. Allow Lokprep a minimum of 10 minutes set up time before applying stress, vacuum or pressure to the connection. (Note in temperatures below 55 F allow 30 minutes)
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THE COLD CLEAN CONNECTION
Internal Cleanliness comparison of a LOKRING Connection and a Brazed Joint. 20