A split type nitrogen generation system adopts a modular separated layout, distributing raw air pretreatment units, separation mainframes, buffer gas storage units and automatic control assemblies across different zones within the plant. It suits sites with limited space and scattered gas-consuming workstations. In long-term operation, the whole system is exposed to compressed air, moisture, oil mist, dust and corrosive substances in the ambient environment. Material selection for each functional unit directly governs equipment stability, service life, gas quality and long-term operation expenditure. Material grade is not an isolated selection criterion. It must be planned holistically according to medium characteristics, working pressure, ambient temperature and humidity, explosion-proof and anti-corrosion requirements. Differentiated material specification for individual sections balances reliability, adaptability and overall investment.

　　Air pipelines form the fundamental carrier for medium transport, where rust resistance, air tightness and cleanliness are primary considerations. Common options include carbon steel, galvanized steel and stainless steel pipes. In dry, clean indoor environments with fully deoiled and dried feed air, galvanized tubing offers convenient fabrication and relatively low upfront cost. Nevertheless, in high-humidity zones or locations with trace corrosive agents, or processes requiring strict gas cleanliness, peeling galvanized layers introduce particulate contaminants that damage downstream separation assemblies, making stainless steel the preferred alternative. There are distinctions among stainless steel grades. Grade 304 is widely used for general air transfer to withstand routine moisture erosion; grade 316L is specified for coastal salt-spray or petrochemical trace-corrosion environments, delivering superior resistance to intergranular corrosion and preventing pitting leakage. Flanges, fittings and gaskets must match the pipe material. Direct coupling of dissimilar metals triggers galvanic corrosion and leakage risks.

　　Filter units serve as the first purification barrier. The material combination of filter supports, housings and seals defines filtration performance. Filter support frames are available in plastic, coated carbon steel and stainless steel. Plastic frames are lightweight and economical for low-pressure, ambient-temperature non-corrosive conditions yet prone to deformation and ageing under heat. Coated carbon steel frames provide higher rigidity and pressure tolerance, though rusting occurs once the coating is scratched. Stainless steel supports maintain stable performance and are widely used for precision pre-filters. Filter media are selected by intercepted contaminants: glass fibre composite media for oil removal and polyester for dust capture. Nitrile rubber is the standard seal material for compressed-air applications with stable oil resistance. Fluororubber seals replace nitrile rubber when acidic or alkaline vapours exist to prevent swelling and seal failure. Filter housings also match working conditions: aluminium housings are lightweight and dissipate heat well for small and medium filters, while large high-pressure filter vessels adopt pressure-vessel-grade carbon steel with internal anti-corrosion coatings.

　　The adsorption separation section is the core of the split system. Materials for pressure vessel shells, tower linings, flow guides and adsorbent support screens are critical. Adsorption towers for pressure swing adsorption split nitrogen systems are manufactured from special pressure-vessel carbon steel, subject to non-destructive testing, blast cleaning and specialised internal anti-corrosion coatings to isolate moisture from steel substrates. Stainless steel tower shells are specified for ultra-clean gas supply or corrosive environments. Internal support screens and flow distribution plates endure continuous airflow friction and granular adsorbent abrasion. Stainless steel woven mesh or perforated plates are deployed for adequate wear resistance, preventing screen rupture and adsorbent carry-over into downstream piping. Flow guiding components avoid easily peeling coatings that shed debris into nitrogen streams. Although adsorbents are functional media rather than structural materials, stable internal construction prevents persistent impurity release and preserves adsorbent performance.

　　Buffer storage tanks stabilise pressure and reserve gas, built to pressure vessel standards. Carbon steel tanks are the most prevalent choice with internal and external anti-corrosion treatment for conventional dry air and nitrogen storage. Stainless steel tanks reduce recurring coating maintenance for outdoor, humid or corrosive installations. Safety valves, pressure gauge ports and drain connections must match the tank material. Internal coating quality demands close attention; poor coating peels under airflow scouring and cyclic pressure fluctuation, carrying particulates to downstream stations and disrupting sensitive processes such as laser machining and inert shielding.

　　Valves and actuators regulate gas circuits remotely and switch flow paths. Valve body materials include brass, aluminium alloy, carbon steel and stainless steel. Brass bodies offer cost advantages for low-pressure branches, while stainless steel is preferred for high-pressure or corrosive service. Internal valve seals follow the same material logic as filter assemblies: nitrile rubber for general service and fluororubber for elevated temperatures, trace oil or corrosive vapours. Diaphragms and springs inside solenoid and pneumatic valves are selected for medium compatibility, with stainless steel springs preventing jamming from rust. Split layouts spread pipework and valve points widely. Material incompatibility causes internal or external leakage, destabilising gas pressure and wasting feed gas.

　　Enclosures for control systems, sensor housings and wiring components are specified to match site protection classes. Standard indoor cabinets are fabricated from powder-coated cold-rolled steel plate. Stainless steel control cabinets are adopted for humid, dusty or explosion-proof zones for better dust and corrosion resistance. Sensor probes for pressure and purity measurement contact gas directly: grade 304 stainless steel for clean nitrogen and grade 316L for corrosive atmospheres. PVC cable conduits degrade rapidly outdoors or in corrosive settings, replaced by stainless steel corrugated tubing. Many breakdowns of split nitrogen systems originate not from the main separation unit but from insufficient weathering resistance of electrical and sensing accessories, causing signal drift and short circuits after prolonged environmental exposure.

　　Beyond individual material grades, material compatibility deserves attention. Direct contact between dissimilar metals induces galvanic corrosion in moist media. Rubber seals incompatible with pipe or valve materials swell, harden or crack. Split nitrogen systems cover dispersed locations with varied micro-environments. A single poorly specified component can gradually compromise the whole gas network. Higher-grade materials increase capital outlay and are not universally necessary; selection should be guided by downstream process requirements and site conditions.

　　In summary, material selection for a split type nitrogen generation system is a coordinated engineering task covering pipelines, filter housings, adsorption towers, storage vessels, valves and control accessories. Every medium-contacting component, from raw air intake to nitrogen delivery at dispersed consumption points, collectively determines corrosion resistance, gas tightness, gas cleanliness and equipment lifespan. Rational material specification based on operating conditions mitigates corrosion, rusting and particulate contamination. This unlocks the core strengths of split layouts: flexible piping and distributed gas supply, delivering consistent qualified nitrogen to downstream processes and cutting cumulative costs from unplanned maintenance and spare part replacement.