The fewer fittings and connections, the better. Every connection in your gas delivery system has the potential for leaks; the more fittings you have, the greater the potential. In the illustration below, several gas purification options are depicted:
A: The VICI Metronics gas purifier minimizes the number of fittings.
Total fittings: 2
B: The "Manifold System" has two compression fittings for the system and one organic O-ring seal for each cartridge.
Total fittings: 5 or more
C: A typical "Contaminant Trap" configuration has several components. Before the gas supply even enters the GC there are at least 4 modules.
Total fittings: 8 or more