i never use my wood splitter. cut mostly dead elm they never get too big. at most , only about 10 or 15 feet of the trunk ever need split and a man on the axe for five minutes does not tire and is actually faster than a splitter. If i can lift it with my poor back, it don't need split!
Now if i had big trees i would likley use it..I don't..so...I don't
a 27 ton splitter would require abouta 6 inch cylinder at about 2000 psi or a 5 inch at 2800 psi
my old splitter uses a 5 inch cylinder and runs off the tractor that has about a 12 gallon a min. pump and pushes out about 2000 psi, but it never stalls very often unless i was trying to split oak knots