DFPT fail at 12200

[Gareth Murcutt]

Have machine that is filled with carbon from pump and failing DFPT 12200 / 021 where PDA gets to -120mmHg. Have changed pumpheads and DF filter (black) but still failing. Any help appreciated.
Thanks
Gareth

[Gareth Murcutt]

Update
Have had to change lots of tubing (black) and all three pumpheads. Foundn new DF filter filled with carbon at both ends - changed and m/c passed. Then started to fail at 12650 - membrane movement. All pressures RVFPA/E DDE out and unable to cal. Tried new throttle valves but no change. Eventually found carbon inside balance chanber that intermittently stopped membrane moving. PASSED!!!!!. Now needs cond cal.

[Garry]

Sorry Gareth, only just spotted your post

Had similar at the end of 2013 when the coupling magnet in the end of the degass pump shattered filling the machine with black ferrite magnet.  This took the heater out though all eventually OK following a thorough clean, filter and tubing change.

What hours was the machine on?  Ours was around 17000hrs.  Spoke to another unit that who had experienced the same but I don't think they informed Braun.  Maybe worth letting them know.  I believe at the time micropump would expect the life of a pump to be around 15000hrs with good quality water.  Normally flow rate would drop off as opposed to this.  In our case I think the drive shaft and/or bearing had worn causing the magnet to run slightly off centre and rubbing on the outer casing.  Once the magnet's outer stainless jacket had worn away the magnet fractured releasing its contents.

[Gareth Murcutt]

Many thanks Garry,

Yes took the pumphead apart last week to see if gears had dissolved but found exactly the same as you but on FPA (I think) - at about 14500hrs. Have another one outside the workshop now. Will definitely being speaking to Braun. Also don't want to have to pay for an entire new pumphead if only magnet needs replacing.
Machine looks awful - what did you use to clean it?

Cheers
Gareth

[Garry]

Changed internal tubing, dialyser lines etc.  Physically cleaned out upline tank and replaced inline filters repeatedly after many days of rinsing.  As initially we were unsure as to the possible effect of the contamination we also sent samples off for analysis that all came back fine.

I think you will need to replace the whole pump as the root cause seems to be misaligned bearing/shaft and not the magnet.

Here's the aftermath of ours

[Gareth Murcutt]

Here's ours...

[Matt Waite]

We've had one or two pumps (literally one or two -that's all) suffer this fate -usually at high run hours. Keeping an eye of the colour of the concentrate pickup straws is a good indicator of early stage wear. They take on a feint grey / purple tinge, and at that point it's worth stripping the pump heads to isolate the cause and nip it in the bud.
Another source of this type of contamination is failure of the encapsulation of the flow chamber stroke sensors. Removing MSBK1&2 coils will reveal 'corrosion' of the rubber stick. When more advanced this leads to flow chamber initialisation issues.

[Garry]

Reawakening this thread.  Anybody  come across this issue recently?  We have had a few, on equipment around 2 years old, showing signs of discolouration in the circuit or FVE filter.  Seems to be both flow pumps and/or degass pump. Have possible issue with EP pumps with <4000hrs.  No resulting issues with alarms/operation at this stage, just spotted during PPM.  Will contact supplier for feedback

[Simon Brooke]

We started using Braun Dialogs in 2013 and haven't had any problems with pumps, until our latest batch purchased in March 2020. These have all had problems with Gear Pumps disintegrating internally.

Check if yours is Rev. L. Apparently this batch of Pump Heads are prone to failure.