Sorry, but the question is too nonspecific. Speed depends on ease of access and time to "Pull a Permit" and get into the necessary safety gear to work in a particular process unit.
In an HF-Alky unit, I would be happy to get 10 TML's in an 8-hr day, and would accept 4.
In a pipe rack that has a catwalk, 10 TML's an hour - 80 a day.
Around pumps and Control Valves, accessible standing flat-footed on the ground, 200 or so.
In a Chemical Recovery boiler [burns Black Liquor] in a papermill, with someone buffing the tubes ahead of the inspector, 6000 in 12-hrs is poor to nominal, and 10,000 is pretty good.
