Prepare the work and confirm the components
Before opening a hydraulic connection, isolate the equipment and release stored pressure using the equipment procedure. Consider accumulators, supported loads and trapped fluid. Never loosen or retighten a fitting while it is pressurised. Keep the work area clean and protect open ports and tube ends against contamination.
Check the fitting configuration, tube outside diameter, LL/L/S series, tube wall and material before assembly. Confirm that the body, nut, cutting ring and any seals form an approved combination. Inspect the threads and sealing surfaces for damage. Obtain the assembly instructions for the supplied system, including any requirements for tools, lubrication, preassembly and inspection.
Prepare and support the tube
Cut the tube square using the equipment specified for the system. Remove internal and external burrs without creating an excessive bevel, then clean away chips and debris. Check that the tube end is round, straight and undamaged over the length needed for assembly. Confirm the minimum straight length near a bend before cutting the tube.
Use tubing that meets the specified dimensional, material and hardness requirements. Where support sleeves are required, select the approved size and type. Route the tube so the connection can be assembled without forcing misaligned parts together. Fit suitable tube supports to manage vibration and avoid leaving the fitting to carry unnecessary mechanical loads.
Follow the supplied assembly method
Place the nut and cutting ring on the tube in the correct orientation. Keep the tube firmly against the specified stop during the cutting-ring operation. Use the prescribed preassembly tool or machine where required, particularly when the instructions specify this for stainless steel, larger sizes or a particular connection design.
Apply lubrication only as directed for the components and assembly method. Surface finishes and materials can change friction and tightening behaviour. Use the stated inspection method to confirm that the ring has formed correctly and retained the tube. A visible material collar may be part of a conventional cutting-ring inspection, while other sealing systems use different checks.
Complete the joint using the specified final assembly procedure and hold the body as instructed. There is no single tightening torque or number of turns that applies to every DIN 2353 fitting. Manual preassembly, machine preassembly and different ring designs can require different final assembly steps.
Inspect, commission and maintain the connection
After assembly, check the installation for alignment, support, clearance and cleanliness. Commission and inspect for leakage using the equipment and site procedures. Keep hands away from suspected hydraulic leaks: a small pressurised jet can cause serious injury. If a connection needs correction, isolate and depressurise the system first.
During maintenance, protect dismantled parts and inspect the tube end, ring, nut, body and seals. Replace damaged or unsuitable components. Preserve matched assemblies where the supplied instructions require this, and use the specified reassembly procedure. Reuse depends on component condition and system instructions; repeated disassembly does not justify an unlimited service-life assumption.
- Confirm the tube, series and complete component combination before assembly.
- Use the specified tools and inspection criteria; check tools for wear.
- Retain the supplied assembly instructions with maintenance records.
