red capacitors

I have a box of red, 2500pF, 15kV, 1" diameter capacitors.they are of the
type D70X5R25M15KV and the T.C. is X5R.  well that doesn't mean a whole lot
to me, i am not familiar with them, but maybe someone on the list is.
would the voltage rating on them be a DC rating?  if they are DC and i
wanted to employ them in my coil would parallel strings of 3 in series be
suitable to take care of and AC supply voltage of 9kV?
kevin wahila