Uson SPRINT LC, Owner'S Manual

Page: 124 / 208

Page 124
Burst Testing
In burst testing, Sprint LC looks for devices to open to atmosphere at some
point during pressurization and rapidly drop toward zero pressure. When
the burst occurs in the correct pressure range and time period, Sprint LC
gives a pass indication. Figures 60 and 61. Test engineers often use a burst
test to check pressure relief mechanisms designed to open within a preset
pressure range. Burst tests are also used to check the friction relief-point
of hydraulic and pneumatic devices.
Flow Control
Use the built-in flow control on the back of the tester to set the pressure
increase, also called ramp rate. Trial and error is needed to adjust the flow
control to get the best rate of pressure increase. A burst test is built around
two test conditions:
Peak Pressure (P)
Peak Pressure is a constantly updated value before the burst. Sprint
LC uses the peak pressure reading as the starting point to measure
the event value. After the event the final peak value is compared to
the minimum and maximum burst setpoints to decide whether the
product is accepted or rejected.
Event (E)
Event is the amount of pressure drop from the peak pressure. When
a burst occurs product opens to atmosphere and the pressure begins
to rapidly drop to zero pressure.
Event Value (End of Test Trigger)
Event value is a setpoint entered in the parameters menu. Event value is
the peak pressure minus the event pressure. In other words, how much the
pressure drop is needed from a peak pressure to be considered a real burst.
For example, an event value setting of 0.2 psig means the product must
drop at least 0.2 psig below the peak pressure to trigger an end of test and
a pass/fail decision.