Automotive
Construction
Agriculture
Livestock
Planting
Spray
Straight Adapter Female DKO x Male NPT
This is where Helesul DKO hydraulic adapters (Double Cone O-ring) stand out as the strategic choice for manufacturers and operators who demand unwavering reliability, delivering a robust solution built on versatility, superior sealing, and global compatibility.
- Technical Details
- Applications
- Dimensions Table (NPT)
- Dimensions Table (DKO)
- Standards met: DIN 2353 (L, S) / ISO 8434-1;
- Outside diameters: 6 mm – 42 mm (metric tubes);
- Maximum operating pressure: 420 bar (6,000 PSI);
- Operating temperature: -40°C to +120°C;
- Body material: carbon steel;
- Surface finish: trivalent zinc plating;
- O-ring: NBR 90 Shore A;
- Certification: ISO 9001.
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 system withstands 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 reduces loosening and sustains productivity during extended working hours.
Dump bodies and road trucks
During tipping of dump bodies and platforms, DKO connections support safe and continuous operation, maintaining full sealing throughout 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 thermal 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 operating under constant high pressure, dual sealing prevents progressive fluid loss that degrades force and speed. The result is a more consistent cycle, lower oil consumption, and improved hourly output, especially in continuous industrial operations.
|
|
Nominal Size |
External Thread (Male) [mm] |
External Thread (Male) [mm] |
Internal Thread (D) [mm] |
|
Thread Tip (d1) |
Half Thread (d2) |
|||
|
1/8"-27 |
9,9 |
10,2 |
8,6 |
|
|
1/4"-18 |
13,2 |
13,6 |
11,4 |
|
|
3/8"-18 |
16,6 |
17,1 |
15 |
|
|
1/2"-14 |
20,7 |
21,3 |
18,6 |
|
|
3/4"-14 |
26 |
26,6 |
20,6 |
|
|
1"-11,5 |
32,5 |
33,3 |
24,1 |
|
|
1.1/4"-11,5 |
41,2 |
42 |
30,3 |
|
|
1.1/2"-11,5 |
47,3 |
48,1 |
39 |
|
|
2"-11,5 |
59,3 |
60,1 |
44,9 |
 |
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 |
|
In general, yes, thanks to the metric and UNF options and the use of adapters when necessary. Check the thread/port pair and the machine pattern.
Fewer microleaks, faster assembly and less rework, which translates into more available machines and lower fluid consumption throughout the life cycle.
DKO (Double Cone O-ring) adapters use a double O-ring sealing system, while traditional JICs have only one sealing cone. The DKO system reduces leaks by up to 98% and offers a useful life 3 times longer, with tolerance to multiple assembly and disassembly without loss of efficiency.
NPTF has tighter tolerance and can seal without sealant in fuels. For hydraulics, NPT with PTFE tape offers better cost-benefit and ease of maintenance.
Use PTFE tape if the connection will be retightened periodically. Prefer anaerobic sealant for permanent sealing and greater vibration resistance.
The conical geometry causes the sides of the thread to compress against each other as it is tightened, creating a metallic barrier that is complemented with PTFE tape or anaerobic sealant.
In agricultural hydraulic circuits, sealing failures can bring a harvester to a halt 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 hydraulic adapters (Double Cone O-ring) are engineered for highly reliable 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 a robust construction, they reduce leaks, simplify assembly, and increase equipment availability even under vibration, demanding 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.
