Keeney 1-1/2-in Plastic Washing Machine Trap in the Under Sink Plumbing department at Lowes.com
Do you have to have a p-trap on a washing machine drain? - Quora
The Plumber's Choice 1-1/2 in. Polypropylene P-Trap with Adapter Flange and TPR Washer for Tubular Drain Applications 12812ATP - The Home Depot
Washing machine drain, stand pipe, P-trap considerations | Terry Love Plumbing Advice & Remodel DIY & Professional Forum
Buy Washing machine drain trap online | WÜRTH
Washing Machine Standpipes Questions
IAPMO Uniform Codes Spotlight
5 Best Ways to Clean Washing Machine Drain Pipe
installation - installing a P-trap for the washing machine with this layout, will it convert to S-trap or causing problem? - Home Improvement Stack Exchange
Can a laundry sink drain be installed without a trap under it?
Standpipe for a Clothes Washer - Inspection Gallery - InterNACHI®
Ask the Builder: Plumbing just a series of rivers and waterfalls | The Spokesman-Review
FloPlast Washing machine Trap (Dia)40mm | DIY at B&Q
Washing Machine Standpipe...Remedy An S-Trap | Terry Love Plumbing Advice & Remodel DIY & Professional Forum