Probably a dumb plumbing question.....

[bsa0021]

I am installing a 1.5" plastic drain line which runs vertical and then runs down through a "p" trap. I need the vertical pipe to connect to the horizontal pipe (with a slight downward slope). What offers the most efficient flow of water (for washing machine), 2- 90 degree bends or 2- 45 degree bends w/a pipe in between? I would assume the 45s would be the best option, but how do I determine the proper length of pipe to cut to fit in between the 2- 45s considering that the vertical pipe is in a predetermined position?
I hope this makes sense.

 

[Lucky Phil]

Go to the home center and get a 'long' 90* elbow; it has a more gentle curve to it. Measure the inside where the pipe goes into, and add that to your dimension.

 

[Highbeam]

Your washing machine should not be able to overwhelm a 1.5" 90 degree bend. Of course 2-45s will flow better and would be easy to fit up. Realize that you can test fit pieces until you get it right. Then glue it. Pipe is cheap so waste is no big deal.

 

[bjkjoseph]

1.41x the spread is the formula

 

[ironpony]

current plumbing code requires 2" pipe on washing machine drains
the new machines pump out so fast they will overflow a 1.5" pipe
rerun the pipe and add a 2" glued up trap to reduce restriction
my.02 cents

 

[Highbeam]

current plumbing code requires 2" pipe on washing machine drains
the new machines pump out so fast they will overflow a 1.5" pipe
rerun the pipe and add a 2" glued up trap to reduce restriction
my.02 cents

Good info. Wonder what happens when the millions of homes with 1.5" drain lines buy new washers?