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Post by shorty77 on Jul 22, 2024 21:32:22 GMT
I have a machine here braun 9.1a. Had many issues from leak which destroyed the connectors to the water block. When rinsing i get good flow going threw the sol cart system.
when is Dialysis mode, ill watch the flow go backwards. From the Y connector i see fluid pushing to the bottom of the sol cart spike. Then The top has air and not pushing forward to fill from the top.
Ok, so lets start this off with what's was done to this machine
1-Ep. FPE, FPA all swapped out one at a time to verify not issue.
2- Performed calibrations to EP/PDA pressure
3- Replaced Wrong valve that was VEB with correct valve which was causing lots of air into the system
4- Now getting flow to where we can calibrate Temp and condo do to old part broke on accident.
5- replaced VBKS/ VBKO/ Vbicp valves and did not fix problem
6- Put machine in test 1-10 and turned PE pump to 2000 with VEB closed reached above -500
With the VEB opened Ep pressure at -65
7- Double checked flow paths from VBKO/VBKS/VBICP valves by pushing RO water to the cartridge's and all paths are clear
8- DBK spring and cap replaced.
Any further help would be truly appreciated
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Post by SrCusEngr on Jul 23, 2024 20:38:31 GMT
<shorty77> Look at your flow diagram and let's analyze it. The fresh water comes into the top of the water block, EP draws water out from the bottom via a path that both lubricates the piston pumps and bypasses them. Then the water goes to CLOSED VEB (unless in disinfection, when VEB opens), PE and the degas chamber EK, then to FEP and EP inlet. This should be negative pressure and your test shows that it is working properly. So far, so good. Now the water leaves EP 9positive pressure, and is forced through the heater, through TSE and to a junction. The water has only two paths to take with one path being blocked by VBKO. So warm water should normally flow into the warm water side of the Water Block via DBK (500mmHg resistance to open the path). When VBKO opens, DBK momentarily will close because the path of least resistance for the water is through VBKO, RVBO (the upper cartridge spike valve) and into the cartridge. Now, with the cartridge installed, RVBU (the lower cartridge spike valve) is open to allow the solution to flow to the piston pump (BICP) through FBIC. Since the cartridge must fill first before BICP can start drawing water, there will not be any outflow of water from the cartridge, and pressure will start to build up from filling the cartridge and degassing of the bicarbonate. To relieve the pressure and allow more water to fill up the cartridge, when VBKO closes, VBKS opens. Note that VBKS is connected to the top side of the cartridge between VBKO and RVBO. Since VBKO is now closed, and RVBO is open, when VBKS opens, water in the tubing and air from the pressurized cartridge will escape via this path: open RVBO, VBKS, FB, SKBSand into the Water Block. NOTE: I am talking only about the water in the tubing (RO) , not solution from the cartridge flowing backwards. VBKS allowsthe build up of air pressure to escape into the Water Block, but you may see water move backward in the top tubing, briefing. This "burping" of the cartridge is necessary for more3 water to displace the air and degas gasses.
Now that you understand the process, in Test 1.23, you can control VBKO and VBKS. So with the cartridge holder closed, the Swingarm (SPC) will open the spiked valves of the cartridge holder. Remove the tubing from the heater output port. Remove the tubing from FBIC and direct it into a bucket. Open VBKO. Now take a 50/100 cc syringe filled with water and insert it into the tubing removed from the heater output port. Push the plunger and water should flow freely out of FBIC. If not, you will need to find the occlusion or tubing error. To test the VBKS path, you will need to pressurize an empty Solcart with your syringe at the same point (clamp off the tubing to FBIC), by opening VBKO manually, fill with water, then closing VBKO. Do this several times. Then with VBKO closed and pressure built up in the cartridge, pull out Bicarbonate wand from the holder slightly and open VBKS. Some water should spray out of the Bic wand holder and you should hear a whoosh of air and water. If you do all this, you just verified your paths are good.
Hope this helps.
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