This is the puck pressure chart that I copied from this forum calculated for 3k psi:
Puck diameter - 1 1/2" = 1.77 sq. in. at 3k psi = 5,301 lbs. = 2.6 tons pressure needed
Puck diameter - 2" = 3.14 sq. in. at 3k psi = 9,424 lbs. = 4.7 tons pressure needed
Puck diameter - 2 1/2" = 4.9 sq. in. at 3k psi = 14,726 lbs. = 7.4 tons pressure needed
Puck diameter - 3" = 7.0 sq. in. at 3k psi = 21,205 lbs. = 10.6 tons pressure needed