4200 Series Aerospace Filters —
High-Pressure Inline with AS1098 Fittings
Norman 4200 Series Inline Filters are compact, lightweight, high-pressure inline filters engineered for reliable protection of critical aerospace components. Commonly deployed as last chance filters in both manned and unmanned flight applications, the 4200 Series delivers an extraordinarily small footprint across operating pressures suited for the most demanding environments — from ground support equipment to propellant systems.
The 4200 Series is a trusted solution across the aerospace filtration industry — particularly in cryogenic applications including liquid oxygen (LOX), liquid hydrogen (LH₂), and liquid helium (LHe) service. These inline filters are B31.3 compliant and built to AS9100 quality standards. A wide range of port and fitting configurations are available, including 37° flare with AS1098 seal cuts in male fittings — making the 4200 Series the standard specification for programs requiring AS1098 fitting compatibility across hydraulic and propellant circuits.
4200 Series Aerospace Filter Specifications:
The 4200 Series is available in multiple configurations designed to meet AS1098, NPT, flare, and face seal standards across a broad range of aerospace and cryogenic system requirements.
Port Type: Male/Female NPT, 37° Flare, AS1098, Male/Female O-Ring, Compression, Face Seal
Element Types: Stainless Steel Wire Mesh, Porous Sintered, Random Metal Fiber (Available Upon Request)
Filter Materials: 304/304L Stainless Steel, 316/316L S.S., Monel, Inconel, Nickel, A286 S.S.
Micron Rating: .2 – 200 µm (300 ABS) *Element Dependent
Temperature Rating: -320°F – 600°F
Accesories: Lockwire Holes, Backing Plates, Filter Disc
If any of our catalog product does not meet your requirements, we frequently customize filter elements and housings to meet your needs.
4200 Series Cryogenic Filter Capabilities
Norman Filter Company's 4200 inline filters are rated for operating temperatures from -320°F to +600°F, making them ideal for liquid oxygen, liquid hydrogen, and liquid helium service — all common in cryogenic aerospace applications including rocket propellant feed lines, pressurization systems, and ground support equipment.
Cryogenic service demands materials and designs that maintain integrity at extreme low temperatures. The 4200 Series is available in 316L stainless steel, Monel, and Inconel — all proven in LOX and LH₂ service.
Why the 4200 Series is the Industry Standard for Aerospace Inline Filtration
Aerospace engineers specify the 4200 Series for applications where space is constrained and filtration cannot be compromised. Its cantilever element design supports flight applications, while its broad materials compatibility — including Inconel, Monel, A286 stainless steel, and standard 304/316 stainless — ensures performance across oxidizing, cryogenic, and high-temperature fluid environments.
As a certified AS9100 aerospace filter manufacturer, Norman Filter Company provides traceability, certified materials, and engineering support for custom 4200 configurations. Whether your program requires a standard AS1098 fitting configuration or a fully engineered custom solution, the 4200 Series can be tailored to your pressure, port, and element requirements.
| Size |
4200 – 1” HEX |
4200 – 1 ¾” HEX | ||||
|---|---|---|---|---|---|---|
| GPM/SCFM |
5 GPM / 150 SCFM |
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| Port Size |
1/8” – ¼” Pipe, 1/8” – 3/8” Tube, ¼” – 3/8” Compression, 9/16” Face Seal |
3/8” – ½” Pipe, ½” – 1” Tube |
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| Housing Material/Pressure Ratings |
304 and 316 (6,000 PSI) |
304 and 316 (3,000 PSI) |
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| Element Materials |
304 and 316 CRES |
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Frequently Asked Questions
What makes the 4200 Series a "last chance filter"?
The term "last chance filter" refers to a filter positioned immediately upstream of a critical component — its job is to catch any contaminants that may have bypassed upstream filtration before they can cause damage. The 4200 Series is ideal for this role because of its extremely compact form factor, high-pressure capability (up to 6,000 PSI in 304/316 SS), and reliable element retention even in high-flow or high-vibration environments common in aerospace and flight applications. Its small hex size allows placement in tight spaces where larger filter assemblies simply cannot fit.
What is an AS1098 fitting, and why is it specified for aerospace filter applications?
AS1098 is an SAE Aerospace Standard that defines the fitting end dimensions for 37° flared tube connections incorporating a seal ring groove. AS1098 fittings provide a more leak-resistant connection than standard 37° flare alone — the addition of the seal ring groove (also called a seal cut) creates a dual-sealing interface that significantly reduces the risk of fluid loss. This makes AS1098 the preferred fitting standard for aerospace hydraulic and propellant systems where leak integrity is mission-critical. The 4200 Series is available with AS1098 seal cuts in male fittings as a standard configuration option.
Is the 4200 Series compatible with cryogenic fluids like LOX, LH₂, and LHe?
Yes. The 4200 Series is one of the most widely specified inline filters for cryogenic aerospace applications. It is rated from -320°F to +600°F and is available in materials — including 316/316L stainless steel, Monel, and Inconel — that maintain structural integrity and seal performance at extreme low temperatures. The 4200 Series has been used extensively in liquid oxygen (LOX), liquid hydrogen (LH₂), and liquid helium (LHe) service across propellant feed lines, pressurization systems, and cryogenic ground support equipment.
Is the 4200 Series B31.3 compliant?
Yes. The 4200 Series is designed and manufactured to meet ASME B31.3 Process Piping compliance, which governs the design, materials, fabrication, assembly, and testing of process piping systems. B31.3 compliance is frequently required for aerospace ground support, test stand, and propellant handling applications. Norman Filter Company can provide documentation and engineering support for B31.3 pressure rating compliance upon request.
Is Norman Filter Company AS9100 certified for aerospace filter manufacturing?
Yes. Norman Filter Company is an AS9100 certified quality manufacturer. AS9100 is the internationally recognized quality management standard for the aviation, space, and defense industries. This certification ensures that NFC's design, manufacturing, and testing processes meet the rigorous quality and traceability requirements demanded by aerospace programs, including documentation, material certifications, and process controls.
Can the 4200 Series be customized for non-standard port configurations or unique application requirements?
Yes. Norman Filter Company frequently engineers custom 4200 Series configurations for programs that fall outside standard catalog offerings. Custom options include non-standard port types, specialized metallurgy, modified hex sizes, lockwire holes, backing plates, and custom micron ratings. The 4200 Series is also available in configurations beyond the standard 1" and 1¾" hex sizes — including a high-pressure large diameter/hex size variant. Submit a Request for Quote or contact our engineering team to discuss your specific requirements.
Common Applications
- Aerospace Fueling Services
- Cryogenics
- Feed & Fill Lines
- PAO Coolant
- Pilot Circuits
- Propellant Tank Flow & Pressurization Systems
- Shipboard Radar Systems
- Test Stands
- Wellhead Control Panels
