Back-up Rings

Back-up Rings

 

Description

Back-up Rings or Anti-extrusion rings are used to prevent the extrusion of a primary seal in high pressure applications. They are most commonly seen in service with a rubber O-ring, though Back-up rings can be used in conjunction with a variety of primary sealing products.

Back-up Rings do not provide any sealing function, as they are simply intended to reduce the extrusion gap on the low-pressure side, so that an O-ring, or whichever primary seal is being used, can fulfill its sealing function without being damaged.

Available Materials

DescriptionMaterial CodeData Sheet
Unfilled PEEK5001pdfUnfilled PEEK
Glass Filled PEEK5010pdfGlass Filled PEEK
Viton® 90D202pdfViton® 90D
Unfilled PTFE1001pdfUnfilled PTFE
Glass Filled PTFE1024pdfGlass Filled PTFE
NBR 90D101pdfNBR 90D

Alternative materials are available upon request.

Download our Design Guide

kc seals design guide backup rings

pdfBack-up Ring Design Guide

Hardware Design Guidelines & Part Numbers

Back-up Rings are manufactured to support standard SAE AS568 dash sizes. The housings for this combination of AS 568 O-rings and Back-up rings will change from the standard SAE AS568 O-ring housing dimensions, to larger housings dimensions for single acting applications, which only require one Back-up Ring, or even larger for double acting applications which require two. Please see below for more info.

Note: The sizes listed below are all standard profile dimensions, K.C. Seals can and does manufacturer to non-standard housing dimensions.

Dash SizeAH1W1W2
0040.0700.0530.1420.182
0050.0700.0530.1420.182
0060.0700.0530.1420.182
0070.0700.0530.1420.182
0080.0700.0530.1420.182
0090.0700.0530.1420.182
0100.0700.0530.1420.182
0110.0700.0530.1420.182
0120.0700.0530.1420.182
0130.0700.0530.1420.182
0140.0700.0530.1420.182
0150.0700.0530.1420.182
0160.0700.0530.1420.182
0170.0700.0530.1420.182
0180.0700.0530.1420.182
0190.0700.0530.1420.182
0200.0700.0530.1420.182
0210.0700.0530.1420.182
0220.0700.0530.1420.182
0230.0700.0530.1420.182
0240.0700.0530.1420.182
0250.0700.0530.1420.182
0260.0700.0530.1420.182
0270.0700.0530.1420.182
Dash SizeAH1W1W2
0280.0700.0530.1420.182
0290.0700.0530.1420.182
0300.0700.0530.1420.182
0310.0700.0530.1420.182
0320.0700.0530.1420.182
0330.0700.0530.1420.182
0340.0700.0530.1420.182
0350.0700.0530.1420.182
0360.0700.0530.1420.182
0370.0700.0530.1420.182
0380.0700.0530.1420.182
0390.0700.0530.1420.182
0400.0700.0530.1420.182
0410.0700.0530.1420.182
0420.0700.0530.1420.182
0430.0700.0530.1420.182
0440.0700.0530.1420.182
0450.0700.0530.1420.182
0460.0700.0530.1420.182
0470.0700.0530.1420.182
0480.0700.0530.1420.182
0490.0700.0530.1420.182
0500.0700.0530.1420.182
1020.1030.0860.2020.261

Dash SizeAH1W1W2
1030.1030.0860.2020.261
1040.1030.0860.2020.261
1050.1030.0860.2020.261
1060.1030.0860.2020.261
1070.1030.0860.2020.261
1080.1030.0860.2020.261
1090.1030.0860.2020.261
1100.1030.0860.2020.261
1110.1030.0860.2020.261
1120.1030.0860.2020.261
1130.1030.0860.2020.261
1140.1030.0860.2020.261
1150.1030.0860.2020.261
1160.1030.0860.2020.261
1170.1030.0860.2020.261
1180.1030.0860.2020.261
1190.1030.0860.2020.261
1200.1030.0860.2020.261
1210.1030.0860.2020.261
1220.1030.0860.2020.261
1230.1030.0860.2020.261
1240.1030.0860.2020.261
1250.1030.0860.2020.261
1260.1030.0860.2020.261
1270.1030.0860.2020.261
Dash SizeAH1W1W2
1280.1030.0860.2020.261
1290.1030.0860.2020.261
1300.1030.0860.2020.261
1310.1030.0860.2020.261
1320.1030.0860.2020.261
1330.1030.0860.2020.261
1340.1030.0860.2020.261
1350.1030.0860.2020.261
1360.1030.0860.2020.261
1370.1030.0860.2020.261
1380.1030.0860.2020.261
1390.1030.0860.2020.261
1400.1030.0860.2020.261
1410.1030.0860.2020.261
1420.1030.0860.2020.261
1430.1030.0860.2020.261
1440.1030.0860.2020.261
1450.1030.0860.2020.261
1460.1030.0860.2020.261
1470.1030.0860.2020.261
1480.1030.0860.2020.261
1490.1030.0860.2020.261
1500.1030.0860.2020.261
1510.1030.0860.2020.261
1520.1030.0860.2020.261
1530.1030.0860.2020.261

Dash SizeAH1W1W2
1540.1030.0860.2020.261
1550.1030.0860.2020.261
1560.1030.0860.2020.261
1570.1030.0860.2020.261
1580.1030.0860.2020.261
1590.1030.0860.2020.261
1600.1030.0860.2020.261
1610.1030.0860.2020.261
1620.1030.0860.2020.261
1630.1030.0860.2020.261
1640.1030.0860.2020.261
1650.1030.0860.2020.261
1660.1030.0860.2020.261
1670.1030.0860.2020.261
1680.1030.0860.2020.261
1690.1030.0860.2020.261
1700.1030.0860.2020.261
1710.1030.0860.2020.261
1720.1030.0860.2020.261
1730.1030.0860.2020.261
1740.1030.0860.2020.261
1750.1030.0860.2020.261
1760.1030.0860.2020.261
1770.1030.0860.2020.261
1780.1030.0860.2020.261
2010.1390.1180.2370.296
Dash SizeAH1W1W2
2020.1390.1180.2370.296
2030.1390.1180.2370.296
2040.1390.1180.2370.296
2050.1390.1180.2370.296
2060.1390.1180.2370.296
2070.1390.1180.2370.296
2080.1390.1180.2370.296
2090.1390.1180.2370.296
2100.1390.1180.2370.296
2110.1390.1180.2370.296
2120.1390.1180.2370.296
2130.1390.1180.2370.296
2140.1390.1180.2370.296
2150.1390.1180.2370.296
2160.1390.1180.2370.296
2170.1390.1180.2370.296
2180.1390.1180.2370.296
2190.1390.1180.2370.296
2200.1390.1180.2370.296
2210.1390.1180.2370.296
2220.1390.1180.2370.296
2230.1390.1180.2370.296
2240.1390.1180.2370.296
2250.1390.1180.2370.296
2260.1390.1180.2370.296
2270.1390.1180.2370.296

Dash SizeAH1W1W2
2280.1390.1180.2370.296
2290.1390.1180.2370.296
2300.1390.1180.2370.296
2310.1390.1180.2370.296
2320.1390.1180.2370.296
2330.1390.1180.2370.296
2340.1390.1180.2370.296
2350.1390.1180.2370.296
2360.1390.1180.2370.296
2370.1390.1180.2370.296
2380.1390.1180.2370.296
2390.1390.1180.2370.296
2400.1390.1180.2370.296
2410.1390.1180.2370.296
2420.1390.1180.2370.296
2430.1390.1180.2370.296
2440.1390.1180.2370.296
2450.1390.1180.2370.296
2460.1390.1180.2370.296
2470.1390.1180.2370.296
2480.1390.1180.2370.296
2490.1390.1180.2370.296
2500.1390.1180.2370.296
2510.1390.1180.2370.296
2520.1390.1180.2370.296
2530.1390.1180.2370.296
Dash SizeAH1W1W2
2540.1390.1180.2370.296
2550.1390.1180.2370.296
2560.1390.1180.2370.296
2570.1390.1180.2370.296
2580.1390.1180.2370.296
2590.1390.1180.2370.296
2600.1390.1180.2370.296
2610.1390.1180.2370.296
2620.1390.1180.2370.296
2630.1390.1180.2370.296
2640.1390.1180.2370.296
2650.1390.1180.2370.296
2660.1390.1180.2370.296
2670.1390.1180.2370.296
2680.1390.1180.2370.296
2690.1390.1180.2370.296
2700.1390.1180.2370.296
2710.1390.1180.2370.296
2720.1390.1180.2370.296
2730.1390.1180.2370.296
2740.1390.1180.2370.296
2750.1390.1180.2370.296
2760.1390.1180.2370.296
2770.1390.1180.2370.296
2780.1390.1180.2370.296
2790.1390.1180.2370.296

Dash SizeAH1W1W2
2800.1390.1180.2370.296
2810.1390.1180.2370.296
2820.1390.1180.2370.296
2830.1390.1180.2370.296
2840.1390.1180.2370.296
3090.2100.1830.3360.403
3100.2100.1830.3360.403
3110.2100.1830.3360.403
3120.2100.1830.3360.403
3130.2100.1830.3360.403
3140.2100.1830.3360.403
3150.2100.1830.3360.403
3160.2100.1830.3360.403
3170.2100.1830.3360.403
3180.2100.1830.3360.403
3190.2100.1830.3360.403
3200.2100.1830.3360.403
3210.2100.1830.3360.403
3220.2100.1830.3360.403
3230.2100.1830.3360.403
3240.2100.1830.3360.403
3250.2100.1830.3360.403
3260.2100.1830.3360.403
3270.2100.1830.3360.403
3280.2100.1830.3360.403
3290.2100.1830.3360.403
Dash SizeAH1W1W2
3300.2100.1830.3360.403
3310.2100.1830.3360.403
3320.2100.1830.3360.403
3330.2100.1830.3360.403
3340.2100.1830.3360.403
3350.2100.1830.3360.403
3360.2100.1830.3360.403
3370.2100.1830.3360.403
3380.2100.1830.3360.403
3390.2100.1830.3360.403
3400.2100.1830.3360.403
3410.2100.1830.3360.403
3420.2100.1830.3360.403
3430.2100.1830.3360.403
3440.2100.1830.3360.403
3450.2100.1830.3360.403
3460.2100.1830.3360.403
3470.2100.1830.3360.403
3480.2100.1830.3360.403
3490.2100.1830.3360.403
3500.2100.1830.3360.403
3510.2100.1830.3360.403
3520.2100.1830.3360.403
3530.2100.1830.3360.403
3540.2100.1830.3360.403
3550.2100.1830.3360.403

Dash SizeAH1W1W2
3560.2100.1830.3360.403
3570.2100.1830.3360.403
3580.2100.1830.3360.403
3590.2100.1830.3360.403
3600.2100.1830.3360.403
3610.2100.1830.3360.403
3620.2100.1830.3360.403
3630.2100.1830.3360.403
3640.2100.1830.3360.403
3650.2100.1830.3360.403
3660.2100.1830.3360.403
3670.2100.1830.3360.403
3680.2100.1830.3360.403
3690.2100.1830.3360.403
3700.2100.1830.3360.403
3710.2100.1830.3360.403
3720.2100.1830.3360.403
3730.2100.1830.3360.403
3740.2100.1830.3360.403
3750.2100.1830.3360.403
3760.2100.1830.3360.403
3770.2100.1830.3360.403
3780.2100.1830.3360.403
3790.2100.1830.3360.403
3800.2100.1830.3360.403
3810.2100.1830.3360.403
Dash SizeAH1W1W2
3820.2100.1830.3360.403
3830.2100.1830.3360.403
3840.2100.1830.3360.403
3850.2100.1830.3360.403
3860.2100.1830.3360.403
3870.2100.1830.3360.403
3880.2100.1830.3360.403
3890.2100.1830.3360.403
3900.2100.1830.3360.403
3910.2100.1830.3360.403
3920.2100.1830.3360.403
3930.2100.1830.3360.403
3940.2100.1830.3360.403
3950.2100.1830.3360.403
4250.2750.2360.430.509
4260.2750.2360.430.509
4270.2750.2360.430.509
4280.2750.2360.430.509
4290.2750.2360.430.509
4300.2750.2360.430.509
4310.2750.2360.430.509
4320.2750.2360.430.509
4330.2750.2360.430.509
4340.2750.2360.430.509
4350.2750.2360.430.509
4360.2750.2360.430.509

Dash SizeAH1W1W2
4370.2750.2360.4300.509
4380.2750.2360.4300.509
4390.2750.2360.4300.509
4400.2750.2360.4300.509
4410.2750.2360.4300.509
4420.2750.2360.4300.509
4430.2750.2360.4300.509
4440.2750.2360.4300.509
4450.2750.2360.4300.509
4460.2750.2360.4300.509
4470.2750.2360.4300.509
4480.2750.2360.4300.509
4490.2750.2360.4300.509
4500.2750.2360.4300.509
4510.2750.2360.4300.509
4520.2750.2360.4300.509
4530.2750.2360.4300.509
4540.2750.2360.4300.509
4550.2750.2360.4300.509
4560.2750.2360.4300.509
Dash SizeAH1W1W2
4570.2750.2360.430.509
4580.2750.2360.430.509
4590.2750.2360.430.509
4600.2750.2360.430.509
4610.2750.2360.430.509
4620.2750.2360.430.509
4630.2750.2360.430.509
4640.2750.2360.430.509
4650.2750.2360.430.509
4660.2750.2360.430.509
4670.2750.2360.430.509
4680.2750.2360.430.509
4690.2750.2360.430.509
4700.2750.2360.430.509
4710.2750.2360.430.509
4720.2750.2360.430.509
4730.2750.2360.430.509
4740.2750.2360.430.509
4750.2750.2360.430.509