An improved seal and method for providing a watertight compression joint connection between a valve or fitting and a flare end of a copper tubing in a water service. The improvement includes an O-ring seal on a bull nose end of a valve and a frictional material inserted into straight AWWA threads on a male inlet or outlet of the valve to sealingly engage a flared end of the copper tubing to the bull nose end and to frictionally engage a flare nut with the tubing back onto the matching bull nose end of the valve when screwing the flare nut onto the male threads of the valve, respectively.