| ISO |
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ISO or International
Standards Organization was created to establish worldwide standards
for industry. They are responsible for formulation of standards regarding
quality assurance or specific products. The ISO 10380 standard
was developed to help define the industry requirements for design,
manufacture and testing of corrugated metal hose and hose assemblies.
The following is a summary of the various sections covered in this standard.
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| MATERIALS |
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ISO
10380 specification lists the more popular materials used in the manufacture
of corrugated metal hose, braid, ferrules and end fittings. Two of
the most common materials utilized for corrugated metal hose are austenitic
stainless steel and copper based alloys. The specification is very
clear that the material used in manufacturing the corrugated metal
hose shall be selected on the basis of their suitability for forming
or welding and for the application conditions under which they will
operate. Materials other than those listed above may be selected by
agreement between the manufacturer and the user.
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| CRITICAL
DIMENSIONS |
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Details and
requirements specified in this section include hose diameter, bend
radii and overall length tolerances. It is common for manufacturers
to list their nominal hose diameter in published literature. ISO 10380
lists the requirement that the actual hose inside diameter will
be at least 98% of the nominal hose size.
The bend radius
covered in the specification includes nominal static and nominal
dynamic bend radius. Dynamic bend radius is used in cycle life fatigue
testing. There are type 1 and 2 dynamic bend radius values in the
specification. OmegaFlex uses the more stringent type 1 dynamic
bend radius for cycle life fatigue testing. Overall length tolerances
listed in the ISO 10380 are –1% to +3%.
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| DESIGN
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Pressure |
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The specification
lists the maximum permissible pressure ratings to be used in testing
performed in accordance with ISO 10380. |
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Elevated
Temperatures |
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Pressure reduction
for elevated temperature conditions is critical in applying the proper
metal hose for an application. This specification provides for a method
of determining the maximum service pressure for a metal hose assembly
under these conditions.
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Low
Temperatures |
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The materials
listed in the specification, with the exception of carbon steel, do
not need to be derated in low temperature applications down to –392°F
or –200°C. Carbon steel material used for end fittings may be
used to a minimum temperature of –68°F or –20°C. |
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Cycle
Life |
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Corrugated metal
hose bend radius and minimum acceptable cycle life design requirements
are outlined. Values and test criteria for meeting static and dynamic
bend radii are also listed.
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| CONSTRUCTION |
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Hose |
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Manufacturing
and corrugation designs are addressed by the ISO 10380 specification.
Seamless or longitudinally welded tube may be corrugated into annular
or helical corrugation designs. Details of methods for joining or
segmenting metal hose are also listed. |
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Braid |
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ISO 10380 specifications
are broad for the design of the braid. |
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Methods
of Assembly |
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Many different
methods of fitting attachment and unacceptable weld characteristics
are outlined by the ISO 10380 specification. The use of protective
covers is also addressed. |
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| TESTING |
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General
Tests |
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Bend, fatigue
and burst test requirements are defined by ISO 10380. OmegaFlex
performs each of these tests when designing or qualifying our products.
The fatigue test is widely recognized in the metal hose industry as
a standard for cycle life testing. While ISO 10380 lists the
average number of cycles of 50,000 at their specified pressure ratings,
OmegaFlex performs testing at our published maximum working pressure. |
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Production
Tests |
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Several types
of non-destructive testing is addressed by the specification. These
include pressure proof test by hydraulic pressure or pneumatic pressure
and leakage test by pneumatic or vacuum testing. Cleaning and marking
of metal hose assemblies is outlined. |
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