Armor means protective material installed on a brake hose to increase the resistance of the hose or hose assembly to abrasion or impact damage.
Brake hose means a flexible conduit, other than a vacuum tubing connector, manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes. For hose, a dimensional description such as " 1/4-inch hose" refers to the nominal inside diameter. For tubing, a dimensional description such as " 1/4-in tubing" refers to the nominal outside diameter.
Brake hose assembly means a brake hose, with or without armor, equipped with end fittings for use in a brake system, but does not include an air or vacuum assembly prepared by the owner or operator of a used vehicle, by his employee, or by a repair facility, for installation in that used vehicle.
Brake hose end fitting means a coupler, other than a clamp, designed for attachment to the end of a brake hose.
Free length means the linear measurement of hose exposed between the end fittings of a hose assembly in a straight position.
Permanently attached end fitting means an end fitting that is attached by deformation of the fitting about the hose by crimping or swaging, or an end fitting that is attached by use of a sacrificial sleeve or ferrule that requires replacement each time a hose assembly is rebuilt.
Preformed means a brake hose that is manufactured with permanent bends and is shaped to fit a specific vehicle without further bending.
Rupture means any failure that results in separation of a brake hose from its end fitting or in leakage.
Vacuum tubing connector means a flexible conduit of vacuum that
Table I-Maximum Expansion of Free Length Brake Hose, CC/FT
Hydraulic brake hose, inside diameter | Test pressure | |||||
1,000 psi | 1,500 psi | 2,900 psi | ||||
Regular expansion hose | Low expansion hose | Low expansion hose | Regular expansion hose | Regular expansion hose | Low expansion hose | |
1/8 inch, or 3mm, or less | 0.66 | 0.33 | 0.79 | 0.42 | 1.21 | 0.61 |
[GREATER THAN] 1/8 inch or 3mm, to 3/16 inch or 5 mm | 0.86 | 0.55 | 1.02 | 0.72 | 1.67 | 0.91 |
[GREATER THAN] 3/16 inch or 5 mm | 1.04 | 0.82 | 1.30 | 1.17 | * | * |
FIG. 1-EXPANSION TEST APPARATUS
Table II-Hose Lengths
Free length between end fittings, inches | Slack, inches | |
1/8 inch or 3 mm hose or less | More than 1/8 inch or 3 mm hose | |
8 to 151/2, inclusive | 1.750 | |
10 to 151/2, inclusive | 1,000 | |
Over 151/2 to 19 inclusive | 1.250 | |
Over 19 to 24, inclusive | 0.750 |
Table III-Air Brake Hose Dimensions-Inside Diameter (ID) and Outside Diameter (OD) Dimensions in Inches (Millimeters)
Type A-Hose Size-Nominal Inside Diameter | ||||||
1/4 | 5/16 | 3/8 | 7/16 | 1/2 SP(1) | 5/8 | |
Min. I.D. | 0.227 (5.8) | 0.289 (7.3) | 0.352 (8.9) | 0.407 (10.3) | 0.469 (11.9) | 0.594 (15.1) |
Max. I.D. | 0.273 (6.9) | 0.335 (8.5) | 0.398 (10.1) | 0.469 (11.9) | 0.531 (13.5) | 0.656 (16.7) |
Min. O.D. | 0.594 (15.1) | 0.656 (16.7) | 0.719 (18.3) | 0.781 (19.8) | 0.844 (21.4) | 1.031 (26.2) |
Max. O.D. | 0.656 (16.7) | 0.719 (18.3) | 0.781 (19.8) | 0.843 (21.4) | 0.906 (23.0) | 1.094 (27.8) |
Type AI(2)-Hose Size-Nominal Inside Diameter | ||||||
3/16 | 1/4 | 5/16 | 13/32 | 1/2 | 5/8 | |
Min. I.D. | 0.188 (4.8) | 0.250 (6.4) | 0.312 (7.9) | 0.406 (10.3) | 0.500 (12.7) | 0.625 (15.9) |
Max. I.D. | 0.214 (5.4) | 0.281 (7.1) | 0.343 (8.7) | 0.437 (11.1) | 0.539 (13.7) | 0.667 (16.9) |
Min. O.D. | 0.472 (12.0) | 0.535 (13.6) | 0.598 (15.1) | 0.714 (18.1) | 0.808 (20.5) | 0.933 (23.7) |
Max. O.D. | 0.510 (13.0) | 0.573 (14.6) | 0.636 (16.2) | 0.760 (19.3) | 0.854 (21.7) | 0.979 (24.9) |
Type AII(2)-Hose Size-Nominal Inside Diameter | ||||||
3/16 | 1/4 | 5/16 | 13/32 | 1/2 | 5/8 | |
Min. I.D. | 0.188 (4.8) | 0.250 (6.4) | 0.312 (7.9) | 0.406 (10.3) | 0.500 (12.7) | 0.625 (15.9) |
Max. I.D. | 0.214 (5.4) | 0.281 (7.1) | 0.343 (8.7) | 0.437 (11.1) | 0.539 (13.7) | 0.667 (16.9) |
Min. O.D. | 0.500 (12.7) | 0.562 (14.3) | 0.656 (16.7) | 0.742 (18.8) | 0.898 (22.8) | 1.054 (26.8) |
Max. O.D. | 0.539 (13.7) | 0.602 (15.3) | 0.695 (17.7) | 0.789 (20.1) | 0.945 (24.0) | 1.101 (27.9) |
(1) Notes: Type A, sizes 3/8, 7/16, and 1/2 Special can be assembled with reusable end fittings. All sizes can be assembled using permanently-attached (crimped) end fittings.
(2) Types AI and AII, all sizes, can be assembled with reusable or permanently-attached (crimped) end fittings.
Table IV-Air Brake Hose Diameters and Test Cylinder Radii
Nominal hose inside diameter, inches1 | 3/16 | 1/4 | 5/16 | 3/8 | 13/32 | 7/16, 1/2 | 5/8 |
Nominal hose inside diameter, millimeters1 | 4, 5 | 6 | 8 | 10 | 12 | 16 | |
Small test cylinder, radius in inches (millimeters)2 | 1 (25) | 11/2 (38) | 13/4 (45) | 13/4 (45) | 17/8 (48) | 2 (51) | 21/2 (64) |
Large test cylinder, radius in inches (millimeters)3 | 2 (51) | 21/2 (64) | 3 (76) | 31/2 (89) | 31/2 (89) | 4 (102) | 41/2 (114) |
Notes:
1 These sizes are listed to provide test cylinder radii for brake hoses manufactured in these sizes. They do not represent conversions.
2 Small test cylinders are used for the high temperature resistance test.
3 Large test cylinders are used for the low temperature resistance, ozone resistance, and adhesion of wire-reinforced hose tests.
Percent of increase=
[(W3-W4)-(W1-W2)]/(W 1-W2) * 100
Table Accompanying Figure 5-Dimensions in Inches (Millimeters)
Free hose length | Nominal hose inside diameter | Dimensions | |||||||
Position "1" | Position "2" | ||||||||
A | B | C | R(1) | A | B | C | R(1) | ||
10.00 (254) | 3/16, 1/4 | 3.00 (76) | 2.75 (70) | 3.75 (95) | 1.40 (34) | 3.00 (76) | 2.75 (70) | 3.75 (95) | 1.20 (30) |
11.00 (279) | 5/16, 3/8, 13/32 | 3.00 (76) | 3.50 (89) | 4.50 (114) | 1.70 (43) | 3.00 (76) | 3.50 (89) | 4.50 (114) | 1.30 (33) |
14.00 (355) | 7/16, 1/2, 5/8 | 3.00 (76) | 4.00 (102) | 5.00 (127) | 2.20 (56) | 3.00 (76) | 4.00 (102) | 5.00 (127) | 1.80 (46) |
Note (1): This is an approximate average radius.
Table V-Vacuum Brake Hose Test Requirements
Hose inside diameter* | High temperature resistance | Low temperature resistance | Bend | Deformation-collapsed inside diameter (dimension D), inches | ||||
Inches | Millimeters | Hose length, inches | Radius of cylinder, inches | Hose length, inches | Radius of cylinder, inches | Hose length, inches | Maximum collapse of outside diameter, inches | |
7/32 | 5 | 8 | 11/2 | 171/2 | 3 | 7 | 11/64 | 3/64 |
1/4 | 6 | 9 | 11/2 | 171/2 | 3 | 8 | 3/32 | 1/16 |
9/32 | 9 | 13/4 | 19 | 31/2 | 9 | 12/64 | 4/64 | |
11/32 | 8 | 9 | 13/4 | 19 | 31/2 | 11 | 13/64 | 5/64 |
3/8 | 10 | 10 | 13/4 | 19 | 31/2 | 12 | 5/32 | 3/32 |
7/16 | 11 | 2 | 201/2 | 4 | 14 | 17/64 | 5/64 | |
15/32 | 11 | 2 | 201/2 | 4 | 14 | 17/64 | 5/64 | |
1/2 | 12 | 11 | 2 | 201/2 | 4 | 16 | 7/32 | 1/8 |
5/8 | 16 | 12 | 21/4 | 22 | 41/2 | 22 | 7/32 | 5/32 |
3/4 | 14 | 21/2 | 24 | 5 | 28 | 7/32 | 3/16 | |
1 | 16 | 31/4 | 281/2 | 61/2 | 36 | 9/32 | 1/4 |
*These sizes are listed to provide test values for brake hoses manufactured in these sizes. They do not represent conversions.
FIG. 6-BEND TEST OF VACUUM BRAKE HOSE.
Table VI-Dimensions of Test Specimen and Feeler Gage For Deformation Test
Hose inside diameter * | Specimen dimensions (see Fig. 7) | Feeler gage dimensions | |||
in. | mm | Depth (inch) | Length (inch) | Width (inch) | Thickness (inch) |
7/32 | 5 | 3/64 | 1 | 1/8 | 3/64 |
1/4 | 6 | 1/16 | 1 | 1/8 | 1/16 |
9/32 | 1/16 | 1 | 1/8 | 1/16 | |
11/32 | 8 | 5/64 | 1 | 3/16 | 5/64 |
3/8 | 10 | 3/32 | 1 | 3/16 | 3/32 |
7/16 | 5/64 | 1 | 1/4 | 5/64 | |
15/32 | 5/64 | 1 | 1/4 | 5/64 | |
1/2 | 12 | 1/8 | 1 | 1/4 | 1/8 |
5/8 | 16 | 5/32 | 1 | 1/4 | 5/32 |
3/4 | 3/16 | 1 | 1/4 | 3/16 | |
1 | 1/4 | 1 | 1/4 | 1/4 |
*These sizes are listed to provide test values for brake hoses manufactured in these sizes. They do not represent conversions.
FIG. 7-DEFORMED SPECIMEN OF VACUUM BRAKE HOSE
11.1 Construction. Each plastic air brake tubing assembly shall be equipped with permanently attached end fittings or reusable end fittings. Plastic air brake tubing shall conform to the dimensional requirements specified in Table VII. (S12.1)
Table VII-Plastic Air Brake Tubing Dimensions
Nominal tubing outside diameter | Maximum outside diameter | Minimum outside diameter | Nominal inside diameter | Nominal wall thickness | Wall thickness tolerance | |||||
mm | inches | mm | inches | mm | inches | mm | inches | mm | inches | |
1/8 inch | 3.25 | 0.128 | 3.10 | 0.122 | 2.01 | 0.079 | 0.58 | 0.023 | 0.08 | 0.003 |
5/32 inch | 4.04 | 0.159 | 3.89 | 0.153 | 2.34 | 0.092 | 0.81 | 0.032 | 0.08 | 0.003 |
3/16 inch | 4.83 | 0.190 | 4.67 | 0.184 | 2.97 | 0.117 | 0.89 | 0.035 | 0.08 | 0.003 |
1/4 inch | 6.43 | 0.253 | 6.27 | 0.247 | 4.32 | 0.170 | 1.02 | 0.040 | 0.08 | 0.003 |
5/16 inch | 8.03 | 0.316 | 7.82 | 0.308 | 5.89 | 0.232 | 1.02 | 0.040 | 0.10 | 0.004 |
3/8 inch | 9.63 | 0.379 | 9.42 | 0.371 | 6.38 | 0.251 | 1.57 | 0.062 | 0.10 | 0.004 |
1/2 inch | 12.83 | 0.505 | 12.57 | 0.495 | 9.55 | 0.376 | 1.57 | 0.062 | 0.10 | 0.004 |
5/8 inch | 16.00 | 0.630 | 15.75 | 0.620 | 11.20 | 0.441 | 2.34 | 0.092 | 0.13 | 0.005 |
3/4 inch | 19.18 | 0.755 | 18.92 | 0.745 | 14.38 | 0.566 | 2.34 | 0.092 | 0.13 | 0.005 |
6 mm | 6.10 | 0.240 | 5.90 | 0.232 | 4.00 | 0.157 | 1.00 | 0.039 | 0.10 | 0.004 |
8 mm | 8.10 | 0.319 | 7.90 | 0.311 | 6.00 | 0.236 | 1.00 | 0.039 | 0.10 | 0.004 |
10 mm | 10.13 | 0.399 | 9.87 | 0.389 | 7.00 | 0.276 | 1.50 | 0.059 | 0.10 | 0.004 |
12 mm | 12.13 | 0.478 | 11.87 | 0.467 | 9.00 | 0.354 | 1.50 | 0.059 | 0.10 | 0.004 |
16 mm | 16.13 | 0.635 | 15.87 | 0.625 | 12.00 | 0.472 | 2.00 | 0.079 | 0.13 | 0.005 |
Table VIII-Plastic Air Brake Tubing Mechanical Properties
Nominal tubing OD | Burst strength pressure | Supported bend radius1 | Unsupported bend radius2 | Conditioned tensile load | ||||
kPa | Psi | Mm | inches | mm | inches | N | lbf | |
1/8 inch | 6900 | 1000 | 9.4 | 0.37 | 9.4 | 0.37 | 156 | 35 |
5/32 inch | 8300 | 1200 | 12.7 | 0.50 | 12.7 | 0.50 | 178 | 40 |
3/16 inch | 8300 | 1200 | 19.1 | 0.75 | 19.1 | 0.75 | 222 | 50 |
1/4 inch | 8300 | 1200 | 25.4 | 1.00 | 25.4 | 1.00 | 222 | 50 |
5/16 inch | 6900 | 1000 | 31.8 | 1.25 | 38.1 | 1.50 | 334 | 75 |
3/8 inch | 9700 | 1400 | 38.1 | 1.50 | 38.1 | 1.50 | 667 | 150 |
1/2 inch | 6600 | 950 | 50.8 | 2.00 | 63.5 | 2.50 | 890 | 200 |
5/8 inch | 6200 | 900 | 63.5 | 2.50 | 76.2 | 3.00 | 1446 | 325 |
3/4 inch | 5500 | 800 | 76.2 | 3.00 | 88.9 | 3.50 | 1557 | 350 |
6 mm | 7600 | 1100 | 20.0 | 0.75 | 25.4 | 1.00 | 222 | 50 |
8 mm | 6200 | 900 | 31.8 | 1.25 | 38.1 | 1.50 | 334 | 75 |
10 mm | 8200 | 1200 | 38.1 | 1.50 | 38.1 | 1.50 | 667 | 150 |
12 mm | 6900 | 1000 | 44.5 | 1.75 | 63.5 | 2.50 | 890 | 200 |
16 mm | 6000 | 875 | 69.9 | 2.75 | 76.2 | 3.00 | 1446 | 325 |
NOTES: (1) Supported bend radius for tests specifying cylinders around which the tubing is bent. (2) Unsupported bend radius for the collapse resistance test in which the tubing is not supported by a cylinder during bending.
([Conditioned Weight-Initial Weight] ÷ [Initial Weight]) * 100
Table Accompanying Figure 8
Nominal tubing outside diameter | Hole diameter "D" | |
mm | Inches | |
1/8 inch | 3.96 | 0.156 |
5/32 inch | 4.75 | 0.187 |
3/16 inch | 5.54 | 0.218 |
1/4 inch | 7.14 | 0.281 |
5/16 inch | 8.71 | 0.343 |
3/8 inch | 10.31 | 0.406 |
1/2 inch | 13.49 | 0.531 |
5/8 inch | 16.66 | 0.656 |
3/4 inch | 20.32 | 0.800 |
6 mm | 6.80 | 0.268 |
8 mm | 8.80 | 0.346 |
10 mm | 10.80 | 0.425 |
12 mm | 12.80 | 0.504 |
16 mm | 16.80 | 0.661 |
[2 * unsupported bend radius] + [nominal OD of tubing]
[3.14 * [unsupported bend radius]] + [10 * [nominal tubing OD]] + 2 inches
or
[3.14 * [unsupported bend radius]] + [10 * [nominal tubing OD]] + 50 mm
49 C.F.R. §571.106
For FEDERAL REGISTER citations affecting § 571.106, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.govinfo.gov.