Final answer:
The pressure testing of fire extinguishers is covered by NFPA 10, which provides guidelines for their safety, including hydrostatic testing to ensure their integrity.
Step-by-step explanation:
The pressure testing of extinguishers to verify their strength against unwanted rupture is outlined in NFPA 10. The NFPA (National Fire Protection Agency) has several codes and standards for different equipment and situations concerning fire safety. NFPA 10 specifically deals with portable fire extinguishers, including guidelines for their installation, maintenance, operation, and inspection/testing. Pressure testing, also known as hydrostatic testing, ensures that fire extinguishers can withstand the pressure they are subjected to during use without failing.
It's important for safety that the structural integrity of fire extinguishers is maintained, and that they operate correctly in emergency situations. This is why pressure testing is an essential part of the safety standards outlined in NFPA 10.