I keep having critters show up out of the magma and they're smashing my magma pumps, and they seem to be just getting pushed through fortifications (or are they swimming through the 7/7 ones?). The pumps draining from my 4 (yes, four) magma pipes ARE isolated by sumps that use the floor grate trick, which makes the title of the thread I guess a little misleading because it isn't my whole stack getting eaten.
Regardless, I keep having to replace the feeder pumps for the base of my primary pump stack. Fortunately there are 20 of these such feeders, so two or three being down at any given time is OK but annoying. There is also a large "magma capacitor" near the top of the fortress to smooth out flux in the flow rate to the main pumps and to handle surges in use (such as from my magma land mines).
Screw pumps can't pump through floor grates by chance, can they?
Also, the whole system uses 17,400 U of power. My power supply varies between 22,000 and 25,000 so I have room to expand if needed. Yes, I needed to deforest the map to do it, and I have huge underground tree farms.
Alternatively, can I lock my tamed 1100 year old dragon down there? He's not very useful otherwise because he keeps cooking his trainers.
Right now my setup looks a bit like this:
%%< - pump pumping from the left. The < is the output tile.
>%% pump pumping from the right. The > is the output tile.
X = wall
F = carved fortification
m = magma flowing under its own power
M = magma under !!pressure!!
@ = gearbox
| = vertical axle
= is a horizontal axle
S = stairs of any type
_ = floor
. = channel
#= floor grate
Vertical slice
(primary pump stack is actually a head-over-head design but it's simplified here)
XX>%%.X|XXXXXXXSXXXXXXXmmmm
XX.%%<X|XXXXXXXSX....mFmmmm
XX>%%.X|XXXXXXXSX...mmFmmmm
XX.%%<X|XXXXXXXSX..mmmFmmmm
XX>%%.X|XXXXXXXSX.mmmmFmmmm
XX.%%<X|XXXXXXXSXmmmmmFmmmm
XX>%%.X@=======@XmmmmmFmmmm (magma pipe)
XXXXXMM#X.MMM>%%mmmmmmFmmmm
XXXXXXXMMMXXXXmmmmmmmmFmmmm
XXXXXXXXXXXXXXXXXXXXXXXmmmm
mmmmmmmmmmmmm(Magma sea)mmm
Not shown: My raging after I discover a pump has been smashed AGAIN.
On a random note, I can't wait for moving fortress sections so I can make Mashy Spike Plates.