A lot of how we plan gear and equipment replacement is based on manufacturer specifications / recommendations, along with established standards. Some of our standards are:
Helmets - 10 years
Turnout Gear - 8 to 10 years unless excessive wear. Gear is tested and replaced sooner if it doesn't pass.
Gloves - as needed. Excessive wear and they are replaced.
Boots - as needed. Again excessive wear or damage and they are replaced.
Rescue Ropes and Webbing - 5 years whether used or not.
Rescue Harnesses - as needed but usually around 10 years unless excessive wear dictates otherwise.
SCBA - our SCBA ranges in age from 5 years to over 30 years. It is serviced as required, and undergoes rigourous testing every 2 years. We upgraded all of our SCBA units several years ago. We are currently planning and budgeting for a complete replacement in the next couple of years, specifically to meet all the new and upgraded standards. The old units will go into training section, or be donated to other departments.
SCBA Cylinders - most are hydrotested every five years, based on manufacturer specification. Some are still hydrotested every three years. Life cycle on the cylinders is fifteen years, and we budget every year for replacement cylinders. We do not have any aluminum cylinders left in the inventory.
Apparatus - all of our apparatus are on a specified replacement cycle. Engines & Rescue - 20 years. Aerial - 25 years. We have planned replacement dates, through our capital replacement plan, and city budgeting cycle. That being said, we have had to postpone replacement of an engine by a few years, due to other financial pressures on the city.
Hope this helps !!