22-3" DIA. STUDS 
39" BOLT CIRCLE 
LOG 
32" 1.0. 
PRESSURE = 4400 PSI 
TEMPERATURE = 430°F 
\ 
Figure 71. Proprietary gasket used on large pressure vessel closure (Mikesell 
and Brown, 1968). 
A more difficult if no more critical problem (any significant leakage 
appears to be unacceptable at this writing) may arise at the point of contact 
between the steel insert and the bored hole in the rock (B, Figure 57). For 
high pressures at great ocean depths, the total design and placement proce- 
dures could be very difficult and will require the best of the available design 
techniques. The total joint construction as shown is not intended to illustrate 
correct methods, but the potential problems. A very deep steel pressure clo- 
sure (approaching hemispherical) would be an optimum shape for strength, 
but upon seating under pressure would be reduced in diameter and break 
any previously made seal, such as grout. Without a step cut or ground into 
the rock, the axial forces would be very high, and a very long sleeve would 
have to be cemented into place to take the end thrust from the ocean water. 
An optimum design might be such that initial deformation upon loading when 
the cavity is dewatered would provide a calculated preload on an elastomeric 
seal in a ground rock seat, both axially and laterally. 
93 
