General Test
and Inspection Procedures for Hose
An inspection and hydrostatic test should be made at periodic intervals
to determine if a hose is suitable for continued service. A visual
inspection of the hose should be made for loose covers, kinks,
soft spots which might indicate broken or displaced reinforcement.
The couplings or fittings should be closely examined and, if there
is any sign of movement of the hose from the couplings, the hose
should be removed from service. The periodic inspection should
include a hydrostatic test for one minute at 150% of the recommended
working pressure of the hose. An exception to this would be the
woven jacketed fire hose.* During the hydrostatic test, the hose
should be straight, not coiled or in a kinked position. Water is
the usual test medium and, following the test, the hose may be
flushed with alcohol to remove traces of moisture. A regular schedule
for testing should be followed and inspection records maintained.
*Woven jacket fire hose
should be tested in accordance with the
service test provisions contained in
the current edition of National Fire
Protection Association Bulletin No. 1962
- Standard for the Care, Use and Service
Testing of Fire Hose.
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SAFETY WARNING: Before conducting
any pressure tests on hose, provisions must be made to ensure
the safety of the personnel performing the tests and to prevent
any possible damage to property. Only trained personnel using
proper tools and procedures should conduct any pressure tests.
1. Air or any other compressible gas must never be used as the
test media because of the explosive action of the hose should
a failure occur. Such a failure might result in possible damage
to property and serious bodily injury.
2. Air should be removed from the hose by bleeding it through
an outlet valve while the
hose is being filled with the test medium.
3. Hose to be pressure tested must be restrained by placing steel
rods or straps close to each end and at approximate 10 foot (3m)
intervals along its length to keep the hose from "whipping" if
failure occurs; the steel rods or straps are to be anchored firmly
to the test structure but in such a manner that they do not contact
the hose which must be free to move.
4. The outlet end of hose is to be bulwarked so that a blown-out
fitting will be stopped.
5. Provisions must be made to protect testing personnel from
the forces of the pressure media if a failure occurs.
6. Testing personnel must never stand in front of or in back
of the ends of a hose being pressure tested.
7. When liquids such as gasoline, oil, solvent, or other hazardous
fluids are used as the test fluid, precautions must be taken
to protect against fire or other damage should a hose fail and
the test liquid be sprayed over the surrounding area.
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The Rubber Manufacturers Association has
published separately a series of Hose Technical Information bulletins
describing Maintenance, Testing and Inspection recommendations.
Reference should be made to the current RMA Catalog of Publications,
to determine the availability of the latest edition. Bulletins
published as of January 1996 include the following:
Publication No.
IP 11-1-Steam Hose
IP 11-2-Anhydrous Ammonia Hose
IP 11-4-0il Suction and Discharge Hose IP 11-5-Welding Hose
IP 11-7-Chemical Hose
IP 11-8-Fuel Dispensing Hose
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Storage
Rubber hose products in storage can be affected adversely by
temperature, humidity, ozone, sunlight, oils, solvents, corrosive
liquids and fumes, insects, rodents and radioactive materials.
The appropriate method for storing hose depends to a great extent
on its size (diameter and length), the quantity to be stored,
and the way in which it is packaged. Hose should not be piled
or stacked to such an extent that the weight of the stack creates
distortions on the lengths stored at the bottom.
Since hose products vary considerably in size, weight, and length,
it is not practical to establish definite recommendations on
this point. Hose having a very light wall will not support as
much load as could a hose having a heavier wall or hose having
a wire reinforcement. Hose which is shipped in coils or bales
should be stored so that the coils are in a horizontal plane.
Whenever feasible, rubber hose products should be stored in their
original shipping containers, especially when such containers
are wooden crates or cardboard cartons which provide some protection
against the deteriorating effects of oils, solvents, and corrosive
liquids; shipping containers also afford some protection against
ozone and sunlight.
Certain rodents and insects will damage rubber hose products,
and adequate protection from them should be provided.
Cotton jacketed hose should be protected against fungal growths
if the hose is to be stored for prolonged periods in humidity
conditions in excess of 70%.
The ideal temperature for the storage of rubber products ranges
from 50°F to 70° F (10°C to 21°C) with a maximum
limit of 100°F (38°C). If stored below 32°F (0°C),
some rubber products become stiff and would require warming before
being placed in
service. Rubber products should not be stored near sources of
heat, such as radiators, base heaters, etc., nor should they
be stored under conditions of high or low humidity.
To avoid the adverse effects of high ozone concentration, rubber
hose products should not be stored near electrical equipment
that may generate ozone or be stored for any lengthy period in
geographical areas of known high ozone concentration. Exposure
to direct or reflected
sunlight, even through windows, should also be avoided. Uncovered
hose should not be stored under fluorescent or mercury lamps
which generate light waves harmful to rubber.
Storage areas should be relatively cool and dark, and free of
dampness and mildew. Items should be stored on a first-in, first-out
basis, since even under the best of conditions, an unusually
long shelf life could deteriorate certain rubber products.
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