This report presents a cycle test on a SCBA (Self Contained Breathing Apparatus) to verify the wear properties of the rubber coated ends of the spring holding clamps or the spring brackets of the mounting assembly. The tests were requested by Mr. Jay Lippert of Apollo Manufacturing, 900 Colorado Avenue South, Golden Valley MN on February 16, 1999 with the tests completed on June 25, 1999.

The testing was limited to performing the cycle tests and determining the force required to remove the tank from the clamps and providing a summary report of the resu1ts.

RESULTS AND DISCUSSION:

Spring Retaining Clamps showed no appreciable evidence of wear as a result of the cycle test which included a total 63,800 cycles of insertion/removal of the tank into the holding assembly. The plastisol on the inside of the Plastisol dipped ends of the spring clamps were only slightly discolored after the cycle test and the clamp spring showed no weakening. This number of cycles is equivalent to replacing the tank 5 times per day for a period of 35 years.

The force required to remove the tank by pulling from above the upper spring clamp was 65 pounds tobreak the friction of the Plastisol, then 35 pounds to continue pulling from the clamp.

SPECIMEN DESCRIPTION:

The Spring Clamp Assembly consisted of two spring brackets which were bolted to a steel base designed to install within a truck or on the wall. The ends of the spring btackets were dipped in a Plastisol.

TEST METHODS AND EQUIPMENT:

The cycle test was arranged with the SCBA tank mounted stationary to a wood frame. The two spring clamps were mounted to an 8" SCBA cylinder. The cycle speed of the cylinder was set at 20 cycles/minute.

Instrumentation:

• P-3500 Strain Indicator (S/N 71171)
• MM 110-030, 2 K Load Cell (cal due 10-10-99)

The test specimens will be held for a period of 30 days and disposed of unless otherwise instructed by the client.

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