pressure range of 0−220 kPa.
A vacuum pump was used to vacuum the system to
0.003 MPa, then the 5th valve was turn off as the 7th valve
was opened. When the pressure of e vessel was increased to
0.1MPa, 7th valve was turn off and the 5th and 6th valves
were opened. Then, turn off 5th and turn on 7th until the pressure
of e vessel was pleased to the required pressure of testing.
At last, turn off 1, 2, 3, 4, 6, 9 valve ports.