Page 200 - Valve Selection Handbook

Pressure Relief Valves 187

system to the chamber H. With the valves in these positions, the chamber
B is depressurized while the compressed air entering the chamber H
assists valve opening.
The control system permits close control of valve opening and closing.
The system may also be adapted for either supplementary loading or lift
assistance only.
Figure 5-25 and Figure 5-26 show two types of direct-loaded pressure
valves for high pressure and high capacity duties in which the loading

Figure 5-25. High Pressure, High-Capacity Safety
Valve Combined with Auxiliary Pneumatic Actuator
for Supplementary Loading and/or Lift Assistance.
(Courtesy of Sempell A. G.)

Figure 5-26. High Pressure, High-Capacity Safety
Valve Combined with Auxiliary Pneumatic Actuator
for Supplementary Loading and/or Lift Assistance.
(Courtesy ofBopp & Reufher.)