K3


High-Pressure Hydraulic Piston Seal

Non-symmetrical piston seal designed to eliminate seal extrusion in high-pressure systems. The integrated positive actuated live rectangular back-up ring eliminates extrusion, yet allows this seal to be fitted when fitment and assembly are more difficult.




Operating Range
MaterialOperating Pressure up toMaximum Pressure up toTemperatureSurface Speed up toFluid, Media Compatability
Duralast 42033,800psi (260bar)5,000psi (350bar)-22°F to 260°F (-30°C to 125°C)1.6ft/s (0.5m/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
Duralast 44035,000psi (350bar)8,000psi (520bar)-22°F to 260°F (-30°C to 125°C)1.6ft/s (0.5m/s)same as Duralast 4203
Duralast 81662,300psi (160bar)3,800psi (260bar)-4°F to 392°F (-20°C to 200°C)3.2ft/s (1.0m/s)fire-resistant fluids, phosphate esters, mineral oils, greases, and most inorganic acids and chemicals, gasoline and gasoline/alcohol blends, hard vacuum
Duralast 51012,300psi (160bar)3,800psi (260bar)-22°F to 212°F (-30°C to 100°C)1.6ft/s (0.5m/s)mineral-oil based hydraulic fluids, silicone greases, petroleum-based oils, water and alcohols
Duralast 61462,300psi (160bar)3,800psi (260bar)-30°F to 302°F (-35°C to 150°C)2.0ft/s (0.7m/s)excellent heat and oil resistance, including exposure to such oil additives as detergents, anti-oxidants and anti-wear agents
Additional standard materials available: High-performance polyurethanes, NBR (Nitrile), FKM, Viton®, HNBR, EPDM, Aflas®, Hytrel®, Silicone, low- and high-temperature, FDA-compliant seal material grades, PTFE, filled PTFE®, engineered thermoplastics and proprietary specialized Duralast™, Duraloy™, and Permachem™ materials.
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. Pressure ratings can be increased by reducing clearances. For pressure above specified operating pressure, please contact engineering@ahpseals.com
Size Table (Inch)Standard range sizes listed below are preferred sizes for new design applications. Seals are available for any bore diameter, cross-section and groove width in 0.001 inch increments, including functional range diameter and optional groove width. Additionally we offer any other seal size as required.
A
Bore Diameter
CS
Cross-Section
D
Groove
Diameter
B*
Gland
Diameter
Tolerance
L
Groove
Width
Standard
L Groove
Width Optional Standards
C
R1
R
Standard Range
Functional Range
Tolerance
D=
B=
D,B
Tol.+0.012/-0
min.
max.
max.
0.500 - 1.249"
0.500 - 3.000"
+0.001/-0
0.125
A - 0.250
A - 0.024
+0/-0.002
0.205
0.137/0.170/0.275
0.055
0.015
0.006
1.250 - 1.449"
0.500 - 8.000"
+0.001/-0
0.125
A - 0.250
A - 0.024
+0/-0.002
0.275
0.137/0.170/0.205
0.055
0.015
0.006
1.500 - 1.999"
0.500 - 10.000"
+0.002/-0
0.188
A - 0.375
A - 0.026
+0/-0.002
0.313
0.205/0.275/0.344/0.413
0.080
0.020
0.006
2.000 - 2.449"
0.500 - 10.000"
+0.003/-0
0.188
A - 0.375
A - 0.026
+0/-0.002
0.344
0.205/0.275/0.313/0.413
0.080
0.020
0.006
2.500 - 4.999"0.750 - 40.000"+0.003/-00.250A - 0.500A - 0.027+0/-0.0030.4130.275/0.344/0.550/0.6200.0800.0200.008
5.000 - 6.249"
1.000 - 45.000"
+0.004/-0
0.313
A - 0.625
A - 0.029+0/-0.004
0.550
0.344/0.413/0.620
0.085
0.025
0.008
6.250 - 11.999"
1.000 - 55.000"
+0.005/-0
0.375
A - 0.750
A - 0.030
+0/-0.005
0.620
0.413/0.550/0.688/0.825
0.090
0.030
0.008
12.000 - 29.999"
2.000 - 60.000"
+0.006/-0
0.500
A - 1.000
A - 0.031
+0/-0.006
0.825
0.550/0.620/0.688/1.100
0.120
0.030
0.008
30.000 - 39.999"
2.500 - 70.000"
+0.007/-0
0.625
A - 1.250
A - 0.032
+0/-0.007
1.030
0.688/0.825/1.100/1.375
0.140
0.030
0.008
40.000 - 49.999"
5.000 - 70.000"
+0.008/-0
0.750
A - 1.500
A - 0.034
+0/-0.008
1.240
0.825/1.100/1.375/1.650
0.170
0.040
0.008
50.000 - 70.000"
6.000 - 70.000"
+0.009/-0
1.000
A - 2.000
A - 0.036
+0/-0.009
1.520
1.100/1.375/1.650
0.230
0.060
0.008
> 70.000"
consult with Ahpseals engineering
* Based on using wear rings. Surface finish: bore (A) Ra 4-12µin – Static (D,L) Ra max. 32µin. See Technical Info for more specific information.

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Seal Housing Drawing