Rotary valve with seal sheet for high purity applications

A rotary valve assembly comprising:

• a first valve comprising a first plate having a through hole and a shaft cavity;
• a second plate having two or more through holes, and a shaft hole;
• and an annular middle plate between the first plate and the second plate, the annular middle plate defining a cavity;
• a rotor plate positioned in the cavity having a first surface and a second surface, a shaft hole, and a through hole;
• a chamber defined by the annular middle plate, the rotor plate, and the first plate;
• the through hole of the first plate being in selective communication with the through hole of the rotor plate, and the through hole of the rotor plate being in selective fluid communication with the two or more through holes of the second plate;
• and
• a seal sheet having two or more openings corresponding to the two or more through holes in the second plate, the seal sheet positioned between a first side of the second plate and a second side of the rotor plate, wherein the seal sheet is not attached to the second plate or the rotor plate, and wherein a top surface of the seal sheet further comprises a low pressure cavity;
• a second valve comprising a first plate having a through hole and a shaft hole;
• a second plate having two or more through holes, and a shaft cavity;
• and an annular middle plate between the first plate and the second plate, the annular middle plate defining a cavity;
• a rotor plate positioned in the cavity having a first surface and a second surface, a shaft hole, and a through hole;
• a chamber defined by the annular middle plate, the rotor plate, and the first plate;
• the through hole of the first plate of the second valve being in selective communication with the through hole of the rotor plate of the second valve, and the through hole of the rotor plate of the second valve being in selective fluid communication with the two or more through holes in the second plate of the second valve;
• a second seal sheet having two or more openings corresponding to the two or more through holes in the second plate of the second valve, the second seal sheet positioned between a first side of the second plate of the second valve and a second side of the rotor plate of the second valve, and wherein the seal sheet is not attached to the second plate of the second valve or the rotor plate of the second valve;
• and
• a shaft extending from the shaft cavity in the second plate of the second valve through the rotor plate and first plate of the second valve and the second plate and the rotor valve of the first valve to the shaft cavity of the first plate of the first valve, the shaft connected to the rotor plate of the first valve and the rotor plate of the second valve for rotating the rotor plate of the first valve and the rotor plate of the second valve.