[lnza4]

Can someone explain to me the two sewer cap openings. One is to the street the other is from the sanitary line from the home. I need to understand. . What the large black 3 or 4 inch pipe that runs from the outside into the area next to the trap that goes under the foundation. Is this called black pipe?

[massplumber2008]

Lnza:

Most likely if you have a running trap (SEE PIC.) in the drain line then all is cast iron pipe until about 10 feet outside the foundation and then the cast iron pipe will most likely transition to another type of pipe. The other type of pipe will be determined by how old the house is.

The house trap (running trap) is obsolete and unnecessary, but is present so just need to clean drain AFTER the trap if possible. It was necessary until they added traps to ALL fixtures in the home.

Let me know what you think... MARK

PS... How did you make out on the clogged drain line..

[ballengerb1]

Lnza, marks got you covered here. Black pipe is what is commonly used for natural gas plumbing in your home. A stack pipe is a vent going up and through your roof.