pressurize

To maintain normal air pressure in (an enclosure, as an aircraft or submarine).

To cause to have or function at greater than normal air or gas pressure.

To put (gas or liquid) under a greater than normal pressure.

To subject to psychological, political, or other nonphysical pressure.

To put pressure on; to put under pressure.

increase the pressure in or of

maintain a certain pressure

increase the pressure on a gas or liquid