Dishwasher Tub Grate. This tub grate (part number WP3369322) is for dishwashers.Tub grate WP3369322 attaches over the dishwasher drain and prevents large debris from redistributing on the dishes.Shut off the house circuit breaker or unplug the dishwasher before installing this part. Wear work gloves to protect your hands.- Dishwasher Tub Grate.