DigitalPrintTechs not on bulk systems is mostly sound BUT. If you are running dual CMYK as most are you cannot remove the H (crossbar) unions. You will lose half your ink channels if you attempt to do so. These machines use a solenoid controlled ink delivery system to switch between cartridges. These only draw ink from ONE of the 2 installed cartridges per color at a time. This is why from the factory these have the H unions on the lines. The only time the H unions are not used is if the printer is configured for anything other than dual CMYK.
There are a couple of bulk ink systems that do not cause problems in the long run. The only ones are those that used a sealed bag system. Triangle has one out, Bordeaux has one, and Mimaki's very own MBIS bulk system uses a sealed bag system. I've gone over this before in other threads. The advantage to a bag system, is that as ink is used the bag of ink collapses. In this scenario the ink system performs as it should. With other bulk systems there is potential for extreme negative and positive pressures being put on the ink train. That will cause issues every time. An ink bag (just like inside a cartridge) collapses as the ink is used, with ink a rigid tank bulk system the tank cannot collapse, as ink is used a good amount of negative pressure is developed which must be overcome until the tank refills the sub cartridge. Does not matter if it uses a float or not, until the float moves some negative pressure is going to build.
I have Triangles EcoBulk system on ours which uses 2 liter ink bags ink boxes. These connect to sub cartridges which also have an ink bag in them. Picture attached. Notice that the bags in the sub cartridges are partially visible, this is so you know for certain that the main bulk bag in the box above is empty, the sub carts bag will start to empty. When it does you simply close the clamp on the line to the bag in the box, pull it off the box, set a new box up, push it's needle into the bottom of it and re-open the clamp. Viola', no air introduced into the ink train, no ink sitting in a tank exposed to a bunch of air above it, no spills, no mess, NO pressure problems. Been using this for several months now and I have to admit, after using about 4 other bulk systems over the years (on a JV3 and JV33), every one has been problematic or messy in it's own way, ink bag bulk systems are by far the best and least problematic bulk systems you can get. Also note, since the sub carts are short 220ml ones you can ditch the big shelf on the printer there giving more room.
Of course these have their own quirks as well. Triangles only uses 4 sub cartridges so you MUST reset the printer when the ink levels run down to 1 or the printer will attempt to switch to the 4 unused slots. Part of the install though is disconnecting the solenoids to those unused slots so it will not be able to try and draw air into the lines since there are no carts there.
I'm actually thinking about maybe adding 4 more of the sub cartridges, reconnecting those 4 selenoid valves, and adding H unions between the main bulk ink boxes and the sub carts so each bulk box can feed 2 sub carts.
