Ideal-Tridon Strapbinder, Руководство по эксплуатации, частям и безопасности

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5.7.1. Hydrostatic Proof Pressure Tests
A proof test is typically conducted for 5 minutes under pressure at twice the working pressure
for a new hose assembly, and one and a half times the working pressure for used assemblies.
For assembly testing, the rating of the component with the lowest rated working pressure
determines the working pressure of the assembly.
Recommended Procedure
For Industrial hose assemblies, it is strongly recommended to use hydrostatic pressure test
methods instead of pneumatic proof testing for safety reasons! Testing with gaseous materials
such as nitrogen or air is absolutely prohibited and can cause injury of death.
A hydrostatic pressure test requires either a hand pump, a power driven hydraulic pump, or an
accumulator system. Connect the hose assembly to the test pump in a straight fashion,
assuring a leak tight connection. It is extremely important that fittings, adapters, and any other
mating components are rated for the pressure value of the test. It is recommended that the
hose assembly be secured in an encapsulated tank that will withstand the pressure, and
secure it with steel rods or straps close to each end and at ten-foot intervals along the length of
the hose. This will prevent it from whipping" if a failure occurs. The securing rods or straps
must be anchored firmly to the test structure, but should not contact the hose. The hose must
be free to move slightly when pressure is applied.
An outlet valve should be applied to the hos e end of the assembly that opposes the test pump
end of the assembly. Unless otherwise specified by the customer, the test media should be
water. Fill the hose with water while the outlet end is raised and the valve slightly opened to
bleed all of the air from the system. Use the outlet valve to bleed all air remaining in the hose.
When all the air has been expelled, close the outlet valve and lower the raised end.
***This is very important as a safety measure because expansion of air compressed in the
hose, when suddenly released by bursting or other failure might result in a serious accident. ***
Next, for reference, mark a line behind the couplings which is at the end of the ferrule, clamp,
band,etc. Then gradually raise the pressure to the desired pressure rating. Hold the pressure
for the time dictated by hose type and conduct a visual inspection. As the pressure is raised,
watch for visual indications of permanent deformation, leakage, and coupling slippage. If any of
these are noted it is cause for rejection. After the test is complete, relieve the test pressure
before disconnecting the hose assembly from the test equipment and drain the water from the
hose. The hose may be flushed with alcohol if all of the water must be removed.
WARNING**WARNING**WARNING**WARNING**WARNING
Wherever particular skills are required, only specially trained persons should engage in those
applications or testing procedures. Failure to do so may result in damage to the hose assembly
or to other personal property and, more importantly, may also result in serious bodily injury.
Hoses must be properly cleaned prior to inspection and testing. This will prevent unexpected
reactions between conveyants and the test media. Always wear safety glasses, gloves, and
protective clothing to protect from leaks or high pressure spray. Also, use shields to protect
people in the work area in the event of a hose burst, spray, or coupling blow-off.
It is recommended to never stand in front of, over, or behind the ends of a hose assembly
during pressure testing. Also make sure that the hose is sufficiently shielded during pressure
testing to stop a coupling in case of a coupling blow-off.
Any failure during testing is likely to be of an explosive nature!
BEST PRACTICES FOR HOSE ASSEMBLY
NAHAD Handbook, Section 5.7.1 (reprint)
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