As per NFPA-24 Section 12.2.1 Aboveground piping for private fire service mains shall not pass through hazardous areas and shall be located so that it is protected from mechanical and fire damage.
API 2218 which is applicable standard for fireproofing says that when Pipeline containing toxic or flammable inventory passing fire hazard zone it supports shall be fireproofed. API 2218 no where says that Pipe itself should be fireproofed.
Although it is not clearly stated in API or NFPA we understand the Fireproofing is NOT required on pipe itself because pipe is filled with water and pipe will never reach its melting temperature as heat would continue to transfer to water. We HOWEVER believe pipe supports must be fireproofed.
I understand from NFPA-24 Section 12.2.1 Protection of above ground fire meaning its supports if any should be protected from the impact fire heat and pipe materiel should not be non metallic and it must be steel.
If pipe materiel is of steel materiel and it is filled with water, it will never fail in fire. Example is sprinklers pipe and deluge pipes are always inside fire hazard.
Please advise if our understanding is correct or not? also let us know if you have any reference or article from NFPA providing more clarity? Please note that the Fire water main is of carbon steel and it is directly on the ground.