Probable Causes Of Pressure Test Failures - Fresenius Medical Care 2008K2 Troubleshooting Manual

•
NPHT: A count down timer that begins at 720 seconds (12 minutes). When it reaches 0 On Line
PHT tests are performed.
•
PHTACT: = 1 when the On Line PHT is running; 0 when not running
•
PHT0: Leak test results of the first BC valve cycle, depending upon which valve cycle was active
when the test began. If less than 25 the valves in this cycle are not leaking.
•
PHT1: Leak test results of the second BC valve cycle, depending upon which valve cycle was
active when the test began. If less than 25 the valves in this cycle are not leaking.
PHT0
Less than 25
More than 25
Less than 25
More than 25

Probable Causes of Pressure Test Failures:

•
Air entering or dialysate escaping through a bad O-ring, bad connection, tubing leak, etc.
•
®
DiaSafe filter leaking or DiaSafe
•
Valves #43 leaking internally
•
Valve #24, #25 leaking internally (if failing On Line PHT ONLY)
•
Balancing chamber valve (#31 through #38) leaking internally
•
Deaeration Pressure too high or too low
•
Dialysate Pressure (Transmembrane Pressure (TMP)) out of calibration specifications
•
Bad UF Pump #22 (with "Fail Get Neg TMP", "Fail Neg Stabilize", "Fail Neg Flow On")
PHT1
Less than 25
Less than 25
More than 25
More than 25 Leak (probably) external to the BC valves
®
filter test valve leaking internally
2008K/K2 Troubleshooting Guide
P/N 507298 Rev. H
Meaning
All BC valves are okay
BC valve leak (first valve cycle)
BC valve leak (second valve cycle)
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