To hook up a portable dishwasher without attaching it to a sink faucet, connect the dishwasher to a water feed for a clothes washer or directly to the hot water line leading to the kitchen sink, recommends DIY-writer Jerry Walch for SFGate. Most portable dishwashers are designed to hook directly to a faucet, but there are kits available that allow these machines to be hooked to alternative sources.
To hook a portable dishwasher to the hot water line, turn off the water leading to the sink. Then, unscrew the pipe between the on-off valve and the line leading to the faucet and install a tee-fitting. A tee-fitting is a simple pipe fitting that adds an additional port to an existing pipe. Use a steel-braided line to connect the portable dishwasher to the tee-fitting. Finally, connect the drain line from the dishwasher to the garbage disposal. Most garbage disposals have a part along the side designed just for this purpose.
Connection kits come with varying lengths of tubing, but the discharge pump on most portable dishwashers is not strong enough to move the water very far. To ensure the water is pumped out effectively, put the dishwasher as close to the kitchen sink as possible.