Would anyone know why im receiving a failed to stabalize error, during test on a Fresenius 2008H machine. I thought it might be valve 43 on the air separator, but I still receive this air intermintent during test??

Have you tried the Hanson O-Rings.
UF checkvalve
bicarb o-ring in wand
UF Port on crooked
dialysate pressure transducer
De-Air Pump Head

Some of these comments have already been made but here is a few things to think about. The Negative Flow Test or Negative Stabilize is a 55 sec test. The TMP indicated must go to at least 260 and stabilize.It then monitors TMP for decay. If greater than 20mmhg test will fail or if TMP did not get to 260.As indicated check the hansen o-rings,UF check valve,particularly the poppet o-ring.This o-ring can become swollen and come off the poppet.Check that all clamps are tight. Look at the flow indicator to see if you can see lots of microbubbles.If you do it is likely that before this test has timed out you will get a filling program,from the bubbles entering air seperator.Valve 43 will then energize and vent the air out and dump your TMP. So you need to try and find the source of all the air. It could be that the deaearation pump head is tired,not maintaining its 24mmhg,etc etc...the list goes on.But try these few things to see if the problem can be resolved. Also try the test at 500 flow.Good Luck

Thanks for the reply, I have tried all the above..The only thing I can think of is that maybe a small amount of air is getting in thru the clamps that may not be tight enough..I even have replaced the air seperator thinking maybe there is a crack that I cant see,,thanks much,,for all the info..Techy

Hi, I've seen that problem reoccuring in several machines. As you know, negative pressure leaks are pretty tough to find. I've had complete success finding them by putting the machine into positive pressure test, and letting it run for about a half an hour. Usually any leaks will make themselves obvious doing this. It helps to completely remove the hydraulics from the machine. It's a crude method, but it works. Good luck!

Swap Air separator and valve 43

Good answers guys - Very Helpful. I print this stuff out and put it in a folder for future problem troubleshooting.

hensen connectors

quote:

Originally posted by Canuck:
Hi, I've seen that problem reoccuring in several machines. As you know, negative pressure leaks are pretty tough to find. I've had complete success finding them by putting the machine into positive pressure test, and letting it run for about a half an hour. Usually any leaks will make themselves obvious doing this. It helps to completely remove the hydraulics from the machine. It's a crude method, but it works. Good luck!

I second the positive pressure test method, if there's a leak it will show it's face most of the time in a positive pressure test...

had the same problem with a H machine... change the UF pump with new one and it fixed the problem.

You all realize this is a seven year old post, right?

probably not i didnt even look until you said something. I have had this happen to a post of mine that was abut a year and a half old and it came back up on the first page when someone gave 2 cents it is kind of funny though

I have had this problem on our fleet of machines.
It was very hard to find due to its intermittent nature.
If you look inside your dialyzer connectors (Hansen)just behind the o-ring you'll often see a small crack. This happened on our 2008K machines around the 22,000 hour time. We now routinely replace our dialyzer connectors at 18K to 20K.
No further problems.
Hope this helps.

quote:

Originally posted by JP:
You all realize this is a seven year old post, right?

I like to read these to see how many people who were here seven years ago are still posting.