Yes, TAPPING is a Scrabble word!

Letter values in Scrabble US: T 1, A 1, P 3, P 3, I 1, N 1, G 2.

Is it a valid word?

TAPPING is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

cut a female screw thread with a tap
draw from or dip into to get something
strike lightly
draw from; make good use of
tap a telephone or telegraph wire to get information
furnish with a tap or spout, so as to be able to draw liquid from it
make light, repeated taps on a surface
walk with a tapping sound
dance and make rhythmic clicking sounds by means of metal plates nailed to the sole of the dance shoes
draw (liquor) from a tap
pierce in order to draw a liquid from
make a solicitation or entreaty for something; request urgently or persistently

Not playable in Scrabble US: TAPDANCE.