Who Else Knows What This Is? Uncommon Plumbing Work

[jar546]

Who can describe what this is from a technical plumbing standpoint?
This is outside the building it serves.

 

[TheCommish]

oil- sand separator, for garage floor drain

 

[e hilton]

The horizontal Y on the smaller riser … far left … looks backwards.

 

[jar546]

oil- sand separator, for garage floor drain

What else do you see?

 

[Joe.B]

House-trap or building trap. Saw it on a ask this old house episode, never seen one in person. They said it was commonplace in old construction to prevent rats from coming into the house.

2022 CPC
1008.0 Building Traps

1008.1 General
Building traps shall not be installed except where required by the Authority Having Jurisdiction. Each building trap where installed shall be provided with a cleanout and with a relieving vent or fresh-air intake on the inlet side of the trap, which needs not be larger than one-half the diameter of the drain to which it connects. Such relieving vent or fresh-air intake shall be carried above grade and terminate in a screened outlet located outside the building.

 

[jar546]

House-trap or building trap. Saw it on a ask this old house episode, never seen one in person. They said it was commonplace in old construction to prevent rats from coming into the house.

2022 CPC
1008.0 Building Traps

1008.1 General
Building traps shall not be installed except where required by the Authority Having Jurisdiction. Each building trap where installed shall be provided with a cleanout and with a relieving vent or fresh-air intake on the inlet side of the trap, which needs not be larger than one-half the diameter of the drain to which it connects. Such relieving vent or fresh-air intake shall be carried above grade and terminate in a screened outlet located outside the building.

Yes, finally. The local sewer authority is run by guys in their 80's and 90's and still require them even though they have no specs that say so. PA, not FL.

 

[Joe.B]

PA Plumbing Code 2018

1002.6 Building Traps
Building (house) traps shall be prohibited.

 

[classicT]

Building trap and what looks like a grease intercept behind.