K is a constant. It will not change, if T = Constant.

Kp = p^2(B)/p^3(A)

Let say pressure p(B) = 10 bar and p(A) = 10 bar

The you get K= (10 bar)^2/ (10 bar)^3 = 0,1 bar^-1

p = nRT/V. R, T = constant, V the volume of the vessel is also constant, then p ~ n.

If pressure for pB rises to 20 bar, then pA will be 15,874 bar.