Dependability: Gas separation units have no moving component parts, thus ensuring exceptional reliability. Membranes are highly resistant to vibration and shocks, chemically inert to greases, moisture-insensitive, and capable of operating over a wide temperature range of –40°С to +60°С.[citation needed] With appropriate maintenance, membrane unit useful life ranges between 130,000 and 180,000 hours (15 to 20 years of continuous operation).[citation needed]