Rubber hydraulic hose and ... - Flipbook - Seite 293
Selection, installation and
maintenance of hose and assemblies
The following recommendations on selection, installation and maintenance of hose assemblies were established in SAE J1273.
Please read these general instructions carefully. More detailed information on many of these subjects is covered in this catalog.
1. Scope
Hose (also includes hose assemblies) has a finite
life and there are a number of factors which will
reduce its life. This recommended practice is
intended as a guide to assist system designers
and/or users in the selection, installation, and
maintenance of hose.
The designers and users must make a systematic review of each application and then select,
install, and maintain the hose to fulfill the
requirements of the application. The following
are general guidelines and are not necessarily a
complete list.
WARNING
Improper selection, installation, or maintenance
may result in premature failures, bodily injury, or
property damage.
2. References
2.1 Applicable documents
The following publications form a part of this
specification to the extent specified herein. The
latest issue of SAE and EN publications shall apply.
2.1.1 SAE, EN and ISO publications
Available from SAE,
400 Commonwealth Drive, Warrendale,
PA 15096-0001.
J516—Hydraulic hose fittings
J517—Hydraulic hose
EN853—Hydraulic hose wire braided
EN854—Hydraulic hose textile reinforced
EN855—Thermoplastic hydraulic hose
EN856—Hydraulic hose wire spiral reinforced
EN857—Hydraulic hose wire braided
ISO 18752:2022 Rubber hoses and hose assemblies
3. Selection
The following is a list of factors which must be
considered before final hose selection can be
made.
3.1 Pressure
After determining the system pressure, hose
selection must be made so that the recommended maximum operating pressure is equal
to or greater than the system pressure. Surge
pressures higher than the maximum operating
pressure will shorten hose life and must be taken
into account by the hydraulic designer.
3.2 Suction
Hoses used for suction applications must be
selected to insure the hose will withstand the
negative pressure of the system.
3.3 Temperature
Care must be taken to insure that fluid and ambient temperatures, both static and transient, do
not exceed the limitations of the hose. Special
care must be taken when routing near hot
manifolds.
3.4 Fluid compatibility
Hose selection must assure compatibility of the
hose tube, cover and fittings with the fluid used.
Additional caution must be observed in hose
selection for gaseous applications.
3.5 Size
Transmission of power by means of pressurized
fluid varies with pressure and rate of flow. The
size of the components must be adequate to
keep pressure losses to a minimum and avoid
damage to the hose due to heat generation or
excessive turbulence.
3.6 Routing
Attention must be given to optimum routing to
minimize inherent problems.
3.7 Environment
Care must be taken to insure that the hose and
fittings are either compatible with or protected
from the environment to which they are exposed.
Environmental conditions such as ultraviolet light,
ozone, salt water, chemicals, and air pollutants
can cause degradation and premature failure and,
therefore, must be considered.
3.8 Mechanical loads
External forces can significantly reduce hose life.
Mechanical loads which must be considered
include excessive flexing, twist, kinking, tensile
or side loads, bend radius, and vibration. Use of
swivel-type fittings or adapters may be required
to insure no twist is put into the hose. Unusual
applications may require special testing prior to
hose selection.
3.9 Abrasion
While hose is designed with a reasonable level
of abrasion resistance, care must be taken to
protect the hose from excessive abrasion which
can result in erosion, snagging and cutting of the
hose cover. Exposure of the reinforcement will
significantly accelerate
hose failure.
3.10 Proper end fitting
Care must be taken to insure proper compatibility
exists between the hose and coupling selected
based on the manufacturer’s recommendations
substantiated by testing to industry standards
such as SAE J517. End fitting components from
one manufacturer are usually not compatible
with end fitting components supplied by another
manufacturer (i.e., using a hose fitting nipple
from one manufacturer with a hose socket from
another manufacturer). It is the responsibility of the
fabricator to consult the manufacturer’s written
instructions or the manufacturer directly for proper
end fitting componentry.
3.11 Length
When establishing proper hose length, motion
absorption, hose length changes due to pressure,
as well as hose and machine tolerances must
be considered.
3.12 Specifications
and standards
When selecting hose, government, industry and
manufacturers’ specifications and recommendations must be reviewed as applicable.
3.13 Hose cleanliness
Hose components vary in cleanliness levels.
Care must be taken to insure that the assemblies
selected have an adequate level of cleanliness for
the application.
3.14 Electrical conductivity
Certain applications require that hose be
nonconductive to prevent electrical current
flow. Other applications require the hose to be
sufficiently conductive to drain off static electricity. Hose and fittings must be chosen with these
needs in mind.
4. Installation
After selection of proper hose, the following factors must be considered by the installer.
EMEA Danfoss rubber hydraulic hose, fitting, tooling and accessories category catalog
293
Danfoss | Safety information
General hose selection information
