This is a job for the Contra Costa water district. TapMaster, Inc. performed a 12″ line stop through an 8″ fitting and because we had the latest technology of a 12 x 8 machine and not a 12 x 12 line stop machine, we were able to fit between the tank and the primary bad valve. Otherwise the city would have had to install a new valve down stream weld on flanges and abandon the 12″ gate valve next to the tank. Instead they just replaced the existing valve.