Indexing valve for regenerative thermal oxidizer

An indexing valve, comprising:

• a valve housing, said valve housing having a housing top, a housing bottom, a housing interior and four ports;
• a top motor mount attached to said housing top, said top motor mount residing on a roof plate of said housing top, said top motor mount further comprising:
• a rigid top beam extending from said housing top, said rigid top beam having an upper flange extending radially therefrom;
• and, a motor mount plate non-integral with said rigid top beam, said motor mount plate disposed on said upper flange over said rigid top beam;
• a diverter assembly within said valve housing, said diverter assembly further comprising:
• a pipe shaft having two pipe shaft ends, said pipe shaft disposed through said valve housing;
• a stub shaft connected to said pipe shaft transitioning vertically from said pipe shaft;
• a diverter blade subassembly connected to said pipe shaft between said pipe shaft ends for rotating within said valve housing, said diverter blade subassembly further comprising a pair of opposing diverter plates, each said diverter plate bent out-of-plane to thereby be curved, wherein a non-cuboidal, large-volume inlet plenum is defined between said diverter plates for receiving fluid flow from one of said four ports;
• a bottom bearing mount attached to said housing bottom, said bottom bearing mount forming a base, wherein said base supports said pipe shaft;
• and,
• a gear motor on said motor mount plate, said gear motor communicating with said stub shaft for driving said diverter blade subassembly within said valve housing to thereby divert said fluid flow to another of said ports.