See http://www.do-it-yourself-pumps.com/...ump-system.htm

Answer from local well drillers - Not needed on 1/2 Hp pump


On Mon, 20 Mar 2006 09:26:27 -0500, dnoyeB wrote:

wrote:
I have a 1/2 HP submersible well pumy on a 40 foot drop pipe which is
capable of pumping about 8 gpm max. The drop pipe is threaded schedule 80
PVC.

Is it necessary to use a torque arrestor?

Thanks.

what is a torque arrestor?