A B767-300 CAPT REPORTS BEING URGED TO FLY AN AIRCRAFT HE FEELS IS UNSAFE.

Narrative

DURING PREFLT PLANNING; I DISCOVERED THAT THE ACFT'S R ENG HIGH PRESSURE BLEED SHUTOFF VALVE WAS INOP. I REFUSED THE ACFT IN THAT CONDITION BECAUSE OF SAFETY CONSIDERATIONS. MAINT DISPATCHED MECH TO GATE TO REPLACE VALVE. DURING REPLACEMENT OF THE VALVE; THE CLAMP HOLDING VALVE TO ENG WAS FOUND TO BE DAMAGED. MECH INFORMED ME THAT HE WOULD RECOMMEND REPLACING CLAMP AS FAILURE OF THE CLAMP WOULD LIKELY RESULT IN A FIRE HAZARD; THOUGH ZZZ DID NOT HAVE THE CLAMP IN STOCK. CLAMP WAS IN STOCK IN ZZZ1. ZZZ ZONE CTLR INFORMED ME THAT DISPATCHER WOULD LIKE TO TALK TO ME. DURING ENSUING PHONE CALL DISPATCHER INFORMED ME THAT THE ACFT ROUTER IN ZZZ2 REQUESTED DISPATCHER TO ASK ME TO FLY THE ACFT AS IS. DISPATCHER SAID ACFT ROUTER TOLD HER TO TELL ME THAT IF I DID NOT FLY THE ACFT AS IS; THE FLT WOULD BE CANCELED RESULTING IN INCONVENIENCE TO THE PAX. I INFORMED THE DISPATCHER THAT I WOULD NOT FLY THAT ACFT UNLESS IT WAS FIXED. ACFT ROUTER PROMPTLY CANCELED THE FLT. I AM VERY UNCOMFORTABLE WITH BEING PUSHED BY A NOT-CERTIFIED PERSON (ACFT ROUTER) TO FLY AN ACFT THAT I HAD PREVIOUSLY REFUSED TO FLY FOR SAFETY CONSIDERATIONS.