K81S


Split Ultra-High Pressure Bi-Directional Hydraulic Piston Seal

Split piston cap seal for high-pressure heavy-duty piston sealing applications. The hard wearing, self-lubricated Nylon cap is step cut for easy installation without special installation tools and provides high extrusion resistance for ultra-high pressure spikes up to 12,500psi. This seal is capable of repeatedly passing over cylinder ports. Rectangular energizer ensures a stable, positive seal and provides continuous contact along the sealing surface.




Operating Range
MaterialOperating Pressure up toMaximum Pressure up toTemperatureSurface Speed up toFluid, Media Compatability
Duraloy 51015,000psi (350bar)10,000psi (700bar)-40°F to 248°F (-40°C to 120°C)3.3ft/s (1m/s)mineral oil-based fluids, fire-resistant water-based hydraulic fluids including HFA and HFB, sea water, biodegradable fluids, vegetable oils, bio-diesels, and most modern hydraulic fluids
*Important Note: Maximum values above depend on extrusion gap, clearances, seal material, media, temperatures, pressures, surface speed, dynamic running surface finish and working environment. Seals cannot be operated at their upper ratings at the same time. For pressure above 3.000psi (210bar)or temperature above 200°F (95°C), please contact engineering for seal material and hardware specification.
Size Table (Inch)The standard range sizes listed below are the preferred sizes for new design applications. Seals are available for any bore size in 0.001inch increments, including functional range. Additionally, we offer any other seal size as required.
A
Bore Diameter
CS
Cross-Section
D
Groove Diameter
B*
Piston Diameter
ToleranceL
Groove Width
CR1R
Standard RangeFunctional RangeToleranceD=B=D,BTol.+0.008/-0min.max.max.
0.312 - 0.564"0.300 - 0.599"+0.001/-00.097A - 0.194A - 0.024+.000/-.0010.0870.0450.0150.006
0.565 - 1.499"0.550 - 1.599"+0.002/-00.148A - 0.296A - 0.024+.000/-.0020.1260.0500.0250.008
1.500 - 3.124"0.550 - 12.000"+0.003/-00.217A - 0.434A - 0.027+.000/-.0030.1650.0700.0250.008
3.125 - 5.249"1.500 - 18.500"+0.003/-00.305A - 0.610A - 0.029+.000/-.0030.2480.1000.0350.008
5.250 - 12.499"3.000 - 26.500"+0.004/-00.414A - 0.828A - 0.030+.000/-.0040.3200.1300.0350.008
12.500 - 26.599"5.000 - 26.500"+0.005/-00.483A - 0.966A - 0.034+.000/-.0050.3200.1300.0350.008
26.600 - 40.124"10.000 - 50.000"+0.007/-00.552A - 1.102A - 0.045+.000/-.0070.3750.1500.0400.012
40.125 - 72.500"20.000 - 72.500"+0.009/-00.748A - 1.496A - 0.050+.000/-.0090.5430.1700.0500.012
> 72.500" consult with Ahpseals engineering
* Based on using wear rings. For pressure above 3,800psi or diameter 26,500", please contact engineering for clearances. Surface finish: rod (A) Ra 4-12µin – Static (D,L) Ra max. 32µin. See Technical Info for more specific information.

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Seal Housing Drawing