sentrybryan
Member
- Location
- Nebraska
Hello all, first post.
Having an issue with cover requirements in an area with CNG compressors. The area has been determined to be Class1Div2 on the print. The issue I have is that i really cant get a full 24" of cover on all my pvc's running thru the area. Having discussed this with AHJ on the phone he is wanting the full 24" or RMC. Problem is, is that this trench has (1) 4", (3) 2-1/2", (25) 1" and (5) 3/4" conduits. In discussng this with a good inspector friend, he was seeing this area under the concrete as unclassified (CNG only is from grade up), and the sealoff first fitting out of the ground essentially blocks the conduit from any fumes. He was reading this as only needing 18" of cover according to Art 300.5.
My backup plan was to see if we could simply encase the conduits in concrete anywhere where I couldn't get the full 24". AHJ kind of scoffed at this. I had done this in the past with inspectors permission on regular gasoline sites. This being subgrade under CNG I would think this would be a no-brainer to pass.
Just wondering what your thoughts/opinions on this matter were. Thank you.
Having an issue with cover requirements in an area with CNG compressors. The area has been determined to be Class1Div2 on the print. The issue I have is that i really cant get a full 24" of cover on all my pvc's running thru the area. Having discussed this with AHJ on the phone he is wanting the full 24" or RMC. Problem is, is that this trench has (1) 4", (3) 2-1/2", (25) 1" and (5) 3/4" conduits. In discussng this with a good inspector friend, he was seeing this area under the concrete as unclassified (CNG only is from grade up), and the sealoff first fitting out of the ground essentially blocks the conduit from any fumes. He was reading this as only needing 18" of cover according to Art 300.5.
My backup plan was to see if we could simply encase the conduits in concrete anywhere where I couldn't get the full 24". AHJ kind of scoffed at this. I had done this in the past with inspectors permission on regular gasoline sites. This being subgrade under CNG I would think this would be a no-brainer to pass.
Just wondering what your thoughts/opinions on this matter were. Thank you.