Blow-off caps must be installed when?

• A. During annual maintenance
• B. After a discharge
• C. They must be installed on installation
• D. Optional and may be left off

Answer: (C)

Blow-off caps are protective closures for the discharge path that keep the system clean and undamaged before it is put into service. They should be installed during installation so the outlet stays protected from dust, moisture, and physical damage as the system is prepared for use. This ensures the discharge path remains ready and reliable when the system is commissioned.

Installing them during installation, rather than waiting for maintenance or after a discharge, aligns with keeping the equipment in a pristine state before it’s first used and with proper commissioning. Leaving caps off during service or after a discharge can allow debris to enter and could compromise performance, and they aren’t optional because the protective function is essential during pre-commissioning. Always follow the manufacturer’s installation instructions for these caps.