Doc. #: A-718C, Rev. 1
Page 22 of 36
6.1.7
Outlet Flange
(item 30)
.
The O-ring groove and the flat gasket surfaces must be free of nicks, scratches
and pits. Similarly, the 1" NPT must be in good condition. If necessary, clean the 1" NPT with a tap.
However, a thread gauge should be used to be sure the thread is not oversized. The standard hand
engagement is 0.400 inches and the acceptable tolerance is plus or minus one full turn (0.087 inches). If
this tolerance is exceeded, the outlet flange must be replaced.
Figure 6-6 Outlet Flange
6.1.8
Pipe Plug
(item 29)
.
Using a wire brush, clean the 1" NPT threads. Inspect for worn, rusted or galled
threads. The proper thread profile is a pointed “V”. Rounded thread will not seal. Replace the pipe plug if
the threads are imperfect.
Figure 6-7 Pipe Plug
6.1.9
Seat Seal
(item 9)
.
If the Teflon
®
seat is deformed by the body sealing to a depth of 1/16", or if it has
embedded debris, discard it. Replace with a new seal. This part is made of a special blend of Teflon
®
and
other materials to provide high strength and resistance to cold flow and is not commercially available except
from Midland.
Figure 6-8 Seat Seal
