Rotary valve with adjustable sealing pressure and devices comprising such valves

A rotary valve comprising:

• a valve housing comprising a cylindrical channel and an end flange, the end flange comprising a pressure port and a through hole, the through hole having a first open end and a second open end and a threaded section between the first and second ends;
• a rotor rotatably mounted in the cylindrical channel of the valve housing and rotatable about a rotation axis, the rotor comprising a contact surface generally perpendicular to the rotation axis;
• a stator slidably mounted inside the valve housing between the rotor and the end flange, the stator comprising a first side facing the contact surface of the rotor and a second side opposite to the first side, the second side of the stator comprising a spring seat;
• a spring comprising a first end and a second end, the first end of the spring received in the spring seat of the stator, the second end of the spring received in the through hole of the end flange through the first open end of the through hole;
• a spring tension adjuster threadedly engaging the threaded section in the through hole of the end flange and pressing the spring towards the stator, the stator in turn biased by the spring towards the rotor, the spring tension adjuster being configured to be rotatable through the second open end of the flange to change an axial position of the spring tension adjuster so as to adjust a tension of the spring compressed between the stator and the end flange.