I have K machines with almost 25K hours on them and I am having a lot of valve issues. I wondered where everyone stands on replacing these. For example lets say you know one of the BC valves is bad, but the problem is very intermittent it doesnt make sense to take the BC out 8 times and keep swapping in a new valve then run the machine for hours to see if its fixed. Does anyone work for a company that makes you know absolutely sure what is wrong before replacing a part? Seems to me that certain situations call for shotgun troubleshooting where you swap in a part to see if it fixes it. I dont like to do that as I enjoy the troubleshooting aspect and like to know exactly what is wrong but sometimes these machines drive you nuts with an intermittent issues. I have tried every way possible to test valves, but ultimately I find that it doesn't guarantee its good. Sometimes you have to take it apart to see what kind of shape the plunger seal is in but at that point you have to throw the valve away anyways as we are not allowed to rebuild them which I can understand. Another question is why is a BC valve $130 through fresenius and a double barbed valve(24, 25, 26) is only $70. They are identical internally and just have different plastic heads on them. Some valves are easier to diagnose than others, for instance sometimes if a valve is always open like v30 during dialysis you can just stint it out with a coupling to see but others like the BC valves are a nightmare. If their leaking off there is a test for that but I find they are normally occluded not leaking. The plunger seal especially after the machine warms up becomes soft an is able to come off the end of the shaft letting it occlude the exist port inside the valve. Ultimately I have been replacing the entire BC assembly($1200) on these high hours machines which always takes care of the issue.
I'm seeing pretty much the same problems. I'm replacing the plunger seals in ALL of the BC valves once I find they are breaking down. 9 out of 10 times V31, 33, 35 and 37 will be the first to go. I would also change the BC membrane at the sametime if it hasn't already been done. Good luck
My strategy (Ours are 30k hrs): Suspected b/c valve take the whole b/c out. Take it apart on bench and replace membranes if at all suspect then proceed to check 2 valves at a time using a power supply and syringe. If I find one or two they get replaced. Of course if several bad replace the whole thing.
Now if that b/c comes back again within a few months the whole thing gets replaced. Yes it's just a matter of the poppet rubbery tip that expands over time but imo not worth rebuilding.
To save a few dollars, you can order the BC valves unharnessed,(without the wiring and connectors)for about $107.00 each. I don't have the part #, but there is one. It will cost you a little less than $900.00 if you want to rebuild that BC with all new valves. It's alot better than the $1200.00. I haven't seen to many wiring harness go bad on the BC.
Single port valve for balance chamber without harness: 674349
Btw, you can download a pdf of the parts manual and use the "ctrl-f" or Find function to search for keywords when looking up parts. The illustrations also help you quickly identify what you need. It sure beats a paper manual or waiting on hold/explaining what you need to Fresenius parts dept.
Thanks bioengie, I should have caught that. That is the same part number on the valve body itself. I don't think the harnesses are a big deal I will just ohm them out when I change valves. Using these and changing the membranes will be less than 900, that's a substantial savings. Now if we can just figure out how to rig up a 200 dialyzer as a diasafe filter we can save a bundle, JK.