wpc
Several states do use the standard plumbing code which require the use of long sweep 90’s in the drainage system, one example is horizontal to vertical where short radius may be used according to code, now what the plumbing inspector will approve is a different story. One solution to the trap is to put a tee in the vent which also makes a good place to clean out the line also. One possible solution, if room is available is to install a laundry tub letting the washer drain into it and letting water that accumlates drain more slowly. Also Many washers are draining at 17 gallons/minute which is a load for a 2in. line, some washers go as high as 22 gal/min.
