Fire Extinguisher Service, Sales And High Pressure Cylinder Hydro-testing. Here at Apex Fire & Safety, we offer complete service of all sizes and types of dry chemical fire extinguishers. Our team can perform monthly inspections at your site. Our shop is equipped with the latest technology in High Pressure hydro-testing for CO2 extinguishers, breathing air cylinders and nitrogen cylinders. We also refill and re-qualify propane cylinders and sell top quality reconditioned cylinder from 5 to 100 lbs.. Contact us today for more information. more... See more text