SAE J20 2022
Superseding J20 MAR2015
SURFACE VEHICLE STANDARD
Coolant System Hoses
This SAE Standard covers reinforced, and flexible hoses intended for use in water and ethylene glycol-based engine-coolant system applications.
1，Added 3.6.4. Added Section 14 for fatigue resistant designator, which defines the pressure cycle requirements and wave form.
14. FATIGUE RESISTANT SERVICE HOSE FR
Any pre-shaped hose type SAE 20R1, 20R3, or SAE 20R4 which maybe operated in a high-fatigue pressure cycling
environment. The letters FR will be used to designate this requirement, for example, SAE 20R3 FR Class D-3.
Main Contents of this profile
3，definitions of hose types
3.1 SAE 20R1 Heavy-duty type for service
in heavy-duty application. This type is available in two wall thicknesses, as indicated in 6.3.
3.2 SAE 20R2 Flexible heavy-duty wire embedded type for the same service as SAE 20R1.
3.3 SAE 20R3 Heater hose for normal service.
3.4 SAE 20R4 Radiator hose for normal service.
3.5 SAE 20R5 Convoluted wire supported type for normal service.
3.6 HOSE SPECIAL DESIGNATORS FOR SAE 20RXY
X refers to the hose type. Y designators may be used for hoses with special features. Multiple Y designators may be used if needed.
This high temperature designation is for any hose type, SAE 20R1 to SAE 20R5, which is required to operate in an environment above 125 °C.
This electrochemical designation is for any hose type, SAE 20R1 to SAE 20R5, which is required to have electrochemical resistance as defined by SAE J1684.
This low temperature designation is for any hose type, SAE 20R1 to SAE 20R5, which is required to operate in an environment down to -55 °C.
This fatigue resistant designation is for any pre-shaped hose type SAE 20R1, 20R3, or 20R4 which is required to operate in a high-fatigue pressure cycling environment.
3.7 HOSE CLASSES
Compounds based on different synthetic rubber grades are specified and designated (see 5.2 for test methods):
Class A—High-temperature resistant
Class B—High oil resistant
Class C—Medium oil resistant
Class D-1—Low oil resistant, improved service
Class D-2—Low oil resistant, standard service
Class D-3—Low oil resistant, high-temperature resistant, premium service
Class E—Low oil resistant, fiber elastomer composite.
4.1，Tube and Cover Thickness
4.3，General Layout Tolerances, Curved Hose
4.6， Finish and Roundness on Connections
5，Physical test requirements and procedures
3）Ozone Test and Requirements
5）Vacuum collapse test
7）Pressure vibration and temperature or pressure and temperature test
5.2，Physical Properties are to be Obtained from Specimens Removed from Hose
2）Tensile Strength and Elongation
6 SAE J20 HEAVY-DUTY TYPE
7 SAE J20 HEAVY-DUTY WIRE EMBEDDED TYPE
8 SAE J20 HEATER HOSE
9 SAE J20 RADIATOR HOSE NORMAL SERVICE TYPE
10 SAE J20 NORMAL SERVICE TYPE CONVOLUTED ,WIRE SUPPORTED HOSE
11 HIGH-TEMPERATURE SERVICE HOSE HT
12 ELECTROCHEMICAL RESISTANT HOSE EC
13 LOW-TEMPERATURE SERVICE HOSE LT
14 FATIGUE RESISTANT SERVICE HOSE FR
15. SHELF LIFE
Refer to military specification MIL-HDBK-695 for SAE J20 hose shelf life, and ARPM Handbook IP-2 for hose storage conditions.
16.1 Revision Indicator
A change bar (I) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only.