I have what I think is a standard plumbing set up in my kitchen, with the laundry machine and dishwasher drains merging with the sink evacuation drain. There have been instances of water backing up. To prevent flooding of the kitchen I'm looking to fit the drain with a backwater valve. The specifications on the drain are: Tubular F 409 PP 1 1/2 tubular. Does there exist such backwater valves for this specification?
UPDATE #1:
Water is backing up due to a common drain problem. When that happens, it doesn't get fixed immediately. In the interim, one needs a fix
UPDATE #2:
I just spoke with a plumber who said it's trivial to install a check valve.
Best Answer
It appears that you have the dishwasher drain hose plumbed directly to the disposal instead of to an air gap. ALSO you have a washing machine plumbed to a tail piece with a dishwasher stub, Both are not "standard". (In the USA)
Washing machines pump water at a significant rate and may be overwhelming your 1 1/2" sink plumbing, 2" is code for washing machine drains.
Adding a check valve is not the correct solution.
The first step it to plumb it properly and then if you still have the issue diagnose the problem.