Energy Northwest in Washington State had an underground 72” water line operating at 28 psi. 
The pipeline needed to be plugged to replace a valve on the downstream side. The 72” pipe was 
excavated and a 72” X 36” Tapping Sleeve was installed on the pipe. A Hot Tap Machine was 
utilized to make a 36” Hot Tap through a 36” line and a Petersen® PeteStop® 129-Series Inflatable Line 
Stop Plug was installed through the 36” Hot Tap Valve under pressure utilizing a plug Launch 
Cylinder. 

The 129-Series Plug was inflated to 56 psi (two times the operating pressure) and the 72” Valve 
was changed out. The Plug was removed from the line and a completion plug installed on the 
tapping sleeve to allow removal of the 36” Valve. A blind flange was then installed on the 
completion valve to complete the job. 

This was a project of Team Industrial Services.