Washing machine drain question

[Lee Schierer]

Has anyone ever heard of a back flow preventer for a washing machine drain stand pipe? Can you provide a link to one?

Added info:
The drain is in the basement.
It drains to a septic system.
The top of the washer stand pipe is more than 18" above where the drain pipe leaves the house.
The stand pipe has a trap to prevent gas back flow.
The washer hose does not fit tight in the standpipe so it will not siphon.

[Erik Loza]

Is the drain line for the washer below the level of the drain line for everything else in the house? That's the only circumstance I could see needing one in. Curious to know as well.

Erik Loza
Minimax USA

[Rich Riddle]

You can look at back water valves. They do make back flow preventers for four inch main lines that you could adapt. Here is a link for you someone else posted on the Internet:

http://www.ndspro.com/images/stories...g-listings.pdf

[George Bokros]

As long as the end of the drain hose is above the outlet of the washer tub and you are draining into an open tub or wall drain I see not need for a back flow preventer. Only if the sewer is blocked will you get a back flow and it would likely drain on the floor before it went down the washer drain hose.

[Jim Koepke]

I remember one kind of similar item from back in the 1950s. Only reason I know about them is my dad used to sell Maytag and Fridgidaire washing machines. They worked as a vacuum break so the washing machine couldn't suck water back in from the drain.

Different plumbing could cause problems with a washing machine.

Sounds like what the OP may be talking about here may also be known as a check valve.

jtk

[Jim Stewart]

A back-flow preventer is available but I wonder why it is needed. The trap is a possible problem because it is a spot where friction will retard the flow. Traps must be plumbed with, "street elbows" that reduce friction. hope this helps.