Danfoss Waltech S Series Hydraulic Fittings (Up to 630 bar)

The Danfoss Waltech S Series (Heavy Duty) is engineered for high-pressure hydraulic systems where performance and safety are critical. Built to DIN 2353 / ISO 8434-1 standards and enhanced with the Guardian Seal corrosion-resistant coating, these fittings offer long service life even in demanding industrial, mobile, and marine environments.
With the standard bite-type design, S Series fittings handle up to 630 bar (size dependent). When paired with the WalringPlus soft-seal cutting ring, working pressure capability increases to 800 bar—making them ideal for extreme applications with pulsating pressures or high vibration.

• Duty Class: Heavy Duty (S Series)
• Tube Outer Diameter Range: 6 mm – 38 mm OD
• Typical Pressure Ratings (Metal Seal): 6–16 mm OD → up to 630 bar, 20–25 mm OD → up to 400 bar, 30–38 mm OD → up to 250 bar
• Typical Pressure Ratings (WalringPlus Soft Seal): Up to 800 bar (depending on tube size)
• Base Material: Mild carbon steel (low-carbon steel)
• Coating: Guardian Seal zinc-based, Cr(VI)-free corrosion protection
• Standards: Manufactured to DIN 2353 and compliant with ISO 8434-1
• Design: Supplied complete with cutting ring and nut; bite-type connection
• Seal Type: Metal-to-metal bite seal (standard) or soft-seal (WalringPlus)

The S Series Heavy Duty fittings are used in some of the most demanding hydraulic systems in the world:

• High-Pressure Industrial Systems – Metal presses, steelworks, injection moulding machines, and forging lines.
• Oil & Gas and Wellhead Equipment – Blowout preventers, subsea hydraulic control panels, and high-integrity connectors.
• Marine & Offshore – Winch drives, steering hydraulics, and deck machinery subject to saltwater exposure.
• Heavy Construction & Mining Machinery – Hydraulic breakers, rock drills, excavators, and tunnelling equipment.
• Energy & Power Generation – Hydro turbine actuators, ESD (Emergency Shut Down) systems, and wind turbine pitch controls.

Why Choose S Series for These Applications?

• Pressure capability up to 800 bar with WalringPlus soft-seal cutting rings.
• Fully compliant with DIN 2353 / ISO 8434-1 for global interchangeability.
• Proven bite-type seal integrity under vibration and pulsating loads.
• Guardian Seal coating for enhanced corrosion resistance.
• Suitable for both static and dynamic high-pressure hydraulic circuits.

• Equal Straight Connector: Connects two tubes of equal OD in a straight run; designed for high-pressure rigidity.
• Male Stud Coupling: Joins metric tube to female-threaded components (BSPP, metric, NPT) in extreme-pressure systems.
• Equal Elbow (90°): Enables directional change in high-pressure tubing runs while maintaining flow integrity.
• Tee Connector (Equal / Reducing): Branches hydraulic flow into multiple circuits; ideal for heavy-duty manifolds.
• Bulkhead Connector: Routes hydraulic lines through structural panels while maintaining system pressure integrity.
• Swivel Connectors: Allows rotational flexibility during assembly and maintenance, reducing strain on tubing.
• End Cap / Plug: Safely seals system ports or tube ends for maintenance, testing, or storage.
• Reducers / Adapters: Joins different tube diameters or thread types while maintaining pressure capability.

Follow these steps for safe, leak-free installation:

1. Prepare the Tube
   • Cut square using a tube cutter or fine-tooth saw.
   • Deburr inside and outside edges.
   • Ensure the tube end is clean and free from surface damage.
2. Fit Components
   • Slide the nut onto the tube, followed by the cutting ring.
   • Push the tube into the fitting body until it seats fully against the internal shoulder.
3. Initial Tightening
   • Hand-tighten until the nut is snug.
   • Using a wrench, tighten according to DIN 2353 heavy-duty guidelines—typically 1 to 1.5 turns beyond finger-tight (refer to torque chart for exact size).
4. Check the Bite
   • Disassemble and inspect for a continuous indentation from the cutting ring around the tube circumference.
   • If the bite is complete, reassemble and tighten to the specified torque.
5. Final Installation
   • Fit the assembly into the system and apply final torque.
   • Avoid over-tightening, as this can damage the sealing surfaces.

Assembly Tips:

• Always match tube material, hardness, and size to the fitting specification.
• For stainless-steel tubes, pre-assembly with a dedicated tool is recommended.
• Guardian Seal coating eliminates the need for lubrication during assembly.