Installation, Operation & Maintenance Manual
12
Top-Transfer 2" Angle Valves A-720, A-721, A-721-B and A-724 Series
5.1.3
BODY.
Inspect the part for corrosive degradation, particularly in the seat, threads, packing sealing and the side port areas.
Clean off these areas to be sure they are free of corrosion, contamination, pits, scratches, etc., that could form leak paths.
The threads are 1/2"-13 for the valve on the side flange. If any of the threads are stripped or corroded, discard the body.
5.1.4
RETAINER ASSEMBLY.
If the Teflon® seat is deformed by the body insert to a depth of 1/16-inch, or if it has embedded
debris, discard it. Replace it with a new seat seal from the factory. This part is custom made for use on Midland valves only
and must be purchased from Midland.
5.1.5
OUTLET FLANGE.
The surfaces where the O-ring fits, and the flat gasket surfaces must be free of nicks, scratches, and pits.
Similarly, the 2" or 3" NPT must be in good condition. It can be cleaned with the standard NPT hand tap. However, a thread
gage should be used to be sure the thread is not oversized. The standard hand-tight engagement is 0.436 inches for the
thread. The acceptable tolerance is plus or minus one thread. If this tolerance is exceeded, a new part must be obtained.
Figure 5.1.5 Outlet Flange
Figure 5.1.3 Valve Body
Figure 5.1.4 Gasket Retainer
