Attaching an ABS P-trap to an ABS Wye Horizontally or Vertically

[Reach4]

These are commercial Washing Machines. They have a 3" waste outlet connection. To the centerline of the waste outlet on the machines is 4.9" from grade (not much to work with). The washers will be mounted on a 6" pedestal raising the waste outlet center height to 10.9" above grade (still not much height). There are no existing drains inside the building. The client does not want the concrete floor cut open to install drains below the concrete because it is pre-tensioned concrete.

No standpipes into the traps? You surely don't want to pump pressure directly into the drain lines.

 

[Victor Kernes]

You can vent your trap arm by hitting the side entry of a san-tee, where the barrel isn't straight up and down, but is rotated 45 degrees.

Residential washing machines pump their discharge up, these machines have a 3" horizontal discharge with no pumping to raise the discharge?

Cheers, Wayne

Good question. I will call the distributor tomorrow and get back to you.
Victor

 

[Sponsor]

 

[Victor Kernes]

You can vent your trap arm by hitting the side entry of a san-tee, where the barrel isn't straight up and down, but is rotated 45 degrees.

Residential washing machines pump their discharge up, these machines have a 3" horizontal discharge with no pumping to raise the discharge?

Cheers, Wayne

Good evening Wayne. Just heard back from the manufacturer's rep. These commercial machines use gravity and non-pressurized drains. I thought you might be on to a great idea by raising the height of the manifold and then pumping upwards, but apparently, that won't work either. So, you are saying if I use a San-Tee for the vent intake on a 45-degree angle off center that is acceptable, as long as the san-tee is not horizontal or vertical? So then I can use the san-tee on the outlet of the P-trap at a 45? And, another idea. Could I put the Street San-Tee on the outlet of the washer, and then attach the P-Trap on the spigot bottom of the tee, and then bring the vent in from the top of the tee? This will basically put the vent on the inlet side of the P-trap. Would this work?
Victor

 

[Reach4]

These are commercial Washing Machines. They have a 3" waste outlet connection.

Output is in the back of the machine?

Will the 4-inch pipe be next to a wall?

How much space is available between the output of the machine and the 4 inch pipe?

 

[wwhitney]

So, you are saying if I use a San-Tee for the vent intake on a 45-degree angle off center that is acceptable, as long as the san-tee is not horizontal or vertical? So then I can use the san-tee on the outlet of the P-trap at a 45?

A san-tee is normally used like this: The through path is vertical, straight up and down. The trap arm comes into the side entry horizontally, the drainage goes out the bottom, and the vent comes off the top. So it's used to take off a vent while simultaneously having the drain turn downward.

What you can do it take that usual orientation and rotate it 45 degrees about the side entry, the trap arm. So if you were looking straight at the horizontal side entry, the top (vent) would be, say, up and to the left, and the bottom (drain) would then be down and to the right.

But if you're trying to minimize height loss as it sounds like you are, you'd surely be better off having the drain exit the vent takeoff on the horizontal. That requires the use of a wye or a combo (wye plus 45) for the vent take off, where the horizontal drain runs through the straight path of the fitting, and the side entry points up (or rolled up to 45 degrees from up).

And, another idea. Could I put the Street San-Tee on the outlet of the washer, and then attach the P-Trap on the spigot bottom of the tee, and then bring the vent in from the top of the tee? This will basically put the vent on the inlet side of the P-trap. Would this work?

Absolutely not, the vent goes after the trap, and as stated previously, for a 3" trap has to be 6" to 72" from the trap weir (the point water first spills out of the trap as it fills up).

Cheers, Wayne

 

[Victor Kernes]

Good question. I will call the distributor tomorrow and get back to you.
Victor

Good morning Wayne. Thought I responded last night. The Commercial Washers are gravity drain, no pressure discharge, so the lines cannot be elevated. How about this configuration, put a Sanitary Tee as the waste connection to the washers, then attach the P-trap to the bottom of the San-tee, and then the top of the San-tee will connect to the vent. Would this be OK to put the vent on top of the inlet to the P-trap? Victor

 

[wwhitney]

Good morning Wayne. Thought I responded last night.

You did, and I responded already. Wayne

 

[Reach4]

What you can do it take that usual orientation and rotate it 45 degrees about the side entry, the trap arm. So if you were looking straight at the horizontal side entry, the top (vent) would be, say, up and to the left, and the bottom (drain) would then be down and to the right.

choice 1, as I think you are describing:
4x4x3 wye in the vertical plane at the floor. Spigot 3x3x3 santee in the 3-inch port of the wye with santee side port pointing horizontally. Then trap into the santee side port.

Top port of the santee may get a spigot 45 to bring the vent up.

 

[Jeff H Young]

Victor, I've never done commercial gravity drain So I'd pick the manufactures brain, in order to get this right