You don't need interrupts for this (unless your compressor or actuator has to be driven on or off in under a millisecond).
How about something like this, with some variables to keep track of the current states of the system. Remember its all being run in a loop, so everything you write should do its stuff then return to the main loop quickly.
I don't know what your system is, but seems the compressor and actuator are actually separate subsystems.
if (pressure < 400)
pressure_OK = false;
pressure_OK = true;
measured_angle = measure_the_angle();
if (measured_angle != desired_angle)
positioned_OK = false;
positioned_OK = true;
if (pressure_OK && positioned_OK)
} // end loop