The flanges on two stainless steel valves were a source of chronic leakage. One valve is an 8” ball valve used in caustic liquor service and the other a 24” gate valve. The customer was using gaskets made of metal inserted PTFE, e-PTFE tape and EPDM rubber to seal the flanges of ball and gate valves. The use of stainless steel bolts limited the amount that the flange could be tightened. Leaks would occur with regularity after installation creating safety and housekeeping issues.