APW3 uses a standard C14 socket like a PC power supply.  The UK cord will be a "kettle cord", the US cord would be same as used for a PC (C13).  However, at 120V an APW3 will not run an s9 - It requires >208V.  Just for reference, an APW3 will power up at any input >85V, but it requires >208V to deliver the power required for an s9.

If you use 208V or 220V outlets for mining in the US, you probably already have a PDU which uses cheap C13-C14 cords to connect to the power supplies.

Hope it helps.