What was found
CABIN PRESSURIZATION CONTROL: DURING CLIMB OUT ~12000-14000' WE HAD AN ECS VALVE 2 FAILURE - PULLED UP THE ECS PAGE AND CONFIRMED IT. APPROXIMATELY 17000' IT CLEARED AND THE CABIN PRESSURE BEGAN TO READJUST (DECREASING). AT APPROXIMATELY 22000-23000' WE RECEIVED THE ECS VALVE 2 FAILURE AGAIN, THIS TIME IT DIDNT EXTINGUISH AMD THE CABIN CONTINUED TO CLIMB TO 10800'. WE STOPPED THE CLIMB AT FL240, TOLD ATC - DONNED THE MASKS, AND BEGAN AN EMEGENCY DESCENT BACK TOWARDS 10000'. WE WERE ENROUTE TO KILM, AND KGSP WAS OFF THE LEFT WINGTIP - WE ADVISED ATC THATS WHERE WE WANTED TO GO - WE VERIFIED GOOD WEATHER, ACCEPTABLE RUNWAY LENGTH AND APPROPRIATE CFR/ GROUND SUPPORT. WITHIN 5 MINUTES OF DECLARING THE EMERGENCY, WE WERE ON FINAL FOR AN "UNEVENTFUL" LANDING ON RWY 4. PICTURES INCLUDED REMOVED FAILED RH FCSOV PN 1300250-11 SN 1663 AND INSTALLED REPAIRED FCSOV PN 1300250-11 SN 1855 WITH NEW ORINGS PN FF200 2-222 IAW PHENOM 300 AMM 21-21-01.