This means that you'll be able to search for NAICS codes directly (if that's your jam). We'll do the math; let's make better data on public procurement together.
Military Chemical Gases; Medical Gases (for medical gases use code 6835); Empty Gas Cylinders and their caps, valves, and valve spare parts.
Possible NAICS Codes
325120 – Industrial Gas Manufacturing
336413 – Other Aircraft Parts and Auxiliary Equipment Manufacturing
324110 – Petroleum Refineries
211130 – Natural Gas Extraction
221210 – Natural Gas Distribution
424690 – Other Chemical and Allied Products Merchant Wholesalers