Description
TA330 Breather Valve
Two-Way Pressure and Vacuum Relief – Without Manual Release
Complies with MIL-DTL-27166 & SAE AS27166
The TA330 breather valve from Arcadia Desiccant is designed for pressure relief applications where a manual release feature is not required. It shares the same performance characteristics as the TA333-R but without the manual push-button. This makes it ideal for sealed containers, transit cases, and other enclosures where automatic pressure equalisation is needed.
The TA330 provides separate and distinct settings for both pressure and vacuum relief. It delivers a flow rate between 1.5 and 4.0 SCFM at 1.5 psi above the reseal pressure. Generally, lower reseal settings correspond to higher flow rates.
The valve is tamper-resistant, maintenance-free, and built from corrosion-resistant materials. It features a silicone rubber seal and a Teflon-coated spherical seat that ensures easy valve opening even after extended periods in storage. Each unit includes a gasket, washer, and hex nut for mounting.
Key Features:
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No manual release – suitable for fully automated systems or sealed containers.
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Comprehensive pressure/vacuum setting range from 0.25 psid to 5.0 psid.
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High flow capability for large enclosures.
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Water jet resistant – tested to IEC 60529 for IPx6 and NEMA 250 (Section 5.7).
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Optional rear-mounted high-flow filter available (can include RFI/EMI shielding).
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RFI/EMI shielding and mounting flanges available.
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Custom desiccant cartridge integration is also supported.
Materials and Finish:
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Housing, Hex Nut & Washer: Aluminium
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Gasket: Silicone rubber (to A-A-59588, Class II, Grade 60)
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Finish: Anodised
Mounting Specifications:
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Mounting Hardware: Supplied (gasket, washer, hex nut)
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Mounting Hole Diameter: 1.05 ± 0.015 in. (27 ± 0.38 mm)
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Maximum Wall Thickness: 0.47 in. (12 mm)
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Installation Torque: 30–40 in-lbs (3.4–4.5 N·m)
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Weight: 0.10 lbs (45 grams)
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For thin walls (<0.063 in. / 2 mm): Add washer (Arcadia P/N 300013-16)
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Threaded Boss Option: 3/4-14 NPSM; counterbore: 1.05 in. ± 0.015 in. x 0.08 in. min depth
Understanding Cracking vs Reseal Valves:
Cracking and reseal valves are mechanically identical—the difference lies in how they are specified.
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Reseal valves are defined by minimum and maximum reseal and crack pressure ranges per MIL-DTL-27166 and SAE AS27166.
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Cracking valves are specified using nominal crack points (e.g. 0.25, 0.5, 1.0 psi), typically preferred when consistent actuation pressure is desired.
Regardless of the label, both types can be selected based on performance characteristics. The most critical metric is often the flow rate at 1.5 psi above the reseal setting.
Valve Sizing Guidance:
Per SAE AS27166, a breather valve should provide a flow rate of at least 12% of the container volume per minute, and this must be achieved below the container’s pressure rating.
For example:
A container of 10 cubic feet, rated for 2 psi, would require a valve that can flow 1.2 SCFM at 2 psid or less. Choosing a valve with a cracking point of 2 psi would not suffice, as the initial flow at crack is minimal (1 cc/min). A valve rated for lower reseal pressure would be more appropriate.
IP and Hose-Down Testing:
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IEC 60529 / IPx6 Testing:
TA330 with a cracking pressure of 0.5 psi or higher passed water jet testing, confirming suitability for IPx6-rated enclosures (when valve is in the closed state). -
NEMA 250 (Section 5.7) Testing:
TA330 valves with 1.0 psi or higher cracking pressure fully prevent water ingress during high-pressure hose-down testing.
For RFI/EMI shielding, mounting options, custom desiccant integrations, or assistance with valve selection, please contact Arcadia Desiccant’s engineering team.
