Washing Machine Valves

[IPDQKWID]

I've read quite a few threads here about upgrading washing machine supply lines, and whether using PEX means that a bump-up in diameter is needed. I am going to be running PEX into my addition, and was thinking about leaving the 3/4" supply all the way to the laundry room. When looking at washing machine valves/outlet boxes/etc, I see almost everything labeled washing machine this or that is 1/2" supply into the valve, with 3/4" male hose threads for the washing machine hoses. Why is that? Does it matter when the supply of 1/2" regulates the flow to the valve? If all machine manufacturers have hose hook-ups for 3/4", why do valves seem to mostly be made for 1/2" supply? A million questions I have, but are the options for supplying the laundry with PEX going to be limited?
An additional question I need help with, if I was going to put together my own configuration, than say buying an Oatey outlet box, are the valves called something special, like boiler drain valve, or does any shut-off valve qualify for laundry applications? Some I see listed as being for 'low water pressure applications' - does residential qualify as low? Thank you.

 

[hj]

The Oatey box will have its own valves and they WILL be 1/2". 3/4" hose on the washers is not the same as 3/4" pipe.

 

[Sponsor]

 

[IPDQKWID]

Ah, thank you for the clarification. I hadn't thought the hose is probably thicker than 1/2" copper, ID probably about the same?

 

[Reach4]

The 3/4 you see written may relate to the garden hose thread connection or the OD of the hose, rather than the ID of the hoses. Did you find a 3/4 ID washing machine supply hose?

1/2 inch PEX will get hot water to the washer quicker than 3/4 inch PEX. 1/2 will have plenty of capacity for filling a home washing machine.

 

[Cacher_Chick]

There is no benefit to over-sizing the supply to the washer, other than that it might fill a bit faster. I've seen washers piped with 3/8 soft copper, and no one knew any different. The commonly available washer boxes with 1/4-turn shut off valves are about as good as need be.