Straight Socket Union Adapter
This is where Helesul DKO (Double Cone O-ring) hydraulic adapters stand out as the strategic choice for manufacturers and operators who refuse to compromise on reliability, delivering a robust solution built on versatility, superior sealing, and global compatibility.
- Technical Details
- Applications
- Dimensions Table (DKO)
- Standards compliance: DIN 2353 (L, S) / ISO 8434-1;
- Outside diameters: 6 mm – 42 mm (metric tubes);
- Maximum operating pressure: 420 bar (6,000 PSI);
- Working temperature: -40°C to +120°C (-40°F to +248°F);
- Body material: carbon steel;
- Surface finish: trivalent zinc plating;
- O-ring: NBR 90 Shore A;
- Certification: ISO 9001.
Combine harvesters and agricultural sprayers
In articulated boom circuits and hydraulic controls exposed to constant vibration and uneven terrain, DKO hydraulic adapters maintain stable sealing, mitigate soil contamination from oil, and reduce corrective interventions. The dual sealing tolerates rapid cycles and pressure spikes typical of field maneuvers, preserving system efficiency.
Tractors and soil preparation implements
In cylinders of reversible plows, leveling harrows, and subsoilers, the 24° profile with O-ring provides a robust connection against impacts and cyclic loads, ensuring precise actuation response. Torque repeatability minimizes loosening and sustains productivity during extended working hours.
Dump trucks and highway trucks
During tipping of beds and platforms, DKO connections contribute to safe, continuous operation, maintaining full sealing across repetitive cycles. High torque resistance helps preserve assembly integrity after maintenance and periodic inspections in road fleets.
Mowers and side sweepers
Exposed to dust, debris, and temperature variations, articulated arm systems benefit from the resilient sealing of the O-ring and conical seat, reducing micro-leaks and maintaining stable pressure. This extends maintenance intervals and optimizes equipment availability.
Presses and compactors
In machines with consistently high pressure, dual sealing prevents progressive fluid losses that degrade force and speed. The result is a more consistent cycle, lower oil consumption, and better output per hour, especially in continuous industrial operations.
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Nominal Sizer |
Tube [mm] |
External Thread (d) [mm] |
Internal Thread (D) [mm] |
|
|
|
Light Series |
Heavy Series |
|
|
|
|
M12x1,5 |
6 |
- |
12 |
10,4 |
|
|
M14x1,5 |
8 |
6 |
14 |
12,4 |
|
|
M16x1,5 |
10 |
8 |
16 |
14,4 |
|
|
M18x1,5 |
12 |
10 |
18 |
16,4 |
|
|
M20x1,5 |
- |
12 |
20 |
18,4 |
|
|
M22x1,5 |
15 |
14 |
22 |
20,4 |
|
|
M24x1,5 |
- |
16 |
24 |
22,4 |
|
|
M26x1,5 |
18 |
- |
26 |
24,4 |
|
|
M30x2 |
22 |
20 |
30 |
27,8 |
|
|
M36x2 |
28 |
25 |
36 |
33,8 |
|
|
M42x2 |
- |
30 |
42 |
39,8 |
|
|
M45x2 |
35 |
- |
45 |
42,8 |
|
|
M52x2 |
45 |
38 |
52 |
49,8 |
|
Use PTFE tape if the connection will be retightened periodically. Prefer anaerobic sealant for permanent sealing and greater vibration resistance.
In agricultural hydraulic circuits, sealing failures can bring a combine harvester to a stop in the middle of harvest and generate high maintenance costs. The dual-sealing system with O-ring helps eliminate leaks even under intense vibration and pressure spikes, reducing unplanned downtime and fluid loss by up to 95% when installed according to specification.
The self-centering 24° cone speeds up assembly by up to 40% compared to conventional fittings, reduces rework, and improves torque repeatability.
Helesul DKO (Double Cone O-ring) hydraulic adapters are engineered for high-reliability sealing in high-pressure hydraulic systems, combining a self-centering 24° cone and O-ring for consistent performance in agricultural machinery and road applications.
With robust construction, they reduce leaks, simplify assembly, and increase equipment availability even under vibration, intense duty cycles, and harsh environments.
All Helesul hydraulic adapters are manufactured in accordance with ISO, SAE, and DIN standards, ensuring interchangeability, safety, and predictable field performance.

