.14 Transportation Mainline Pipeline Construction Industry Optional Expense Substantiation Rules for Payments to Employees Under Accountable Plans. For calendar year 2025, an eligible employer may pay certain welders and heavy equip[1]ment mechanics an amount up to $22 per hour for rig-related expenses that are deemed substantiated under an account[1]able plan if paid in accordance with Rev. Proc. 2002-41, 2002-1 C.B. 1098. If the employer provides fuel or otherwise reim[1]burses fuel expenses, an amount up to $14 per hour is deemed substantiated if paid under Rev. Proc. 2002-41. .