Facing pipe exploding with soot (8)
I believe the answer is:
opposite
'facing' is the definition.
(as in two things facing each other)
'pipe exploding with soot' is the wordplay.
'exploding with' indicates an anagram.
'pipe' anagrammed with 'soot' can make 'OPPOSITE'.
(Other definitions for opposite that I've seen before include "Diametrically contrary" , "Rival" , "Contrary or face-to-face" , "Oppose it, being faced against" , "Directly across from" .)