{"product_id":"new-aeroquip-a-nut-e-155-25-12d-coupling-assembly-ta155-s4-12d-a2061-a1061","title":"AEROQUIP AERO 155-25-12D COUPLING ASSEMBLY TA155-S4-12D","description":"\u003c!-- SEO Introduction --\u003e\n\u003csection class=\"koeed-container\"\u003e\n  \u003ch2 style=\"color: #0056b3;\"\u003eAeroquip AERO 155-25-12D (TA155-S4-12D) Self-Sealing Coupling Assembly\u003c\/h2\u003e\n  \u003cp\u003e\n    The \u003cstrong\u003eAeroquip AERO 155-25-12D\u003c\/strong\u003e (crossover TA155-S4-12D) is a high-performance, \n    self-sealing quick disconnect coupling designed for critical fluid transfer in aerospace and \n    industrial hydraulic systems. Engineered to provide \u003cstrong\u003eminimum spillage\u003c\/strong\u003e and \n    \u003cstrong\u003ezero air inclusion\u003c\/strong\u003e during connection and disconnection, this -12 size (3\/4\") \n    assembly ensures system integrity in high-vibration environments. Its lightweight aluminum \n    construction and precision-engineered seals make it a standard choice for engine test stands, \n    ground support equipment, and cooling circuits.\n  \u003c\/p\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eKeywords:\u003c\/strong\u003e Aeroquip 155 Series, Self-Sealing Coupling, TA155-S4-12D, Quick Disconnect Hydraulic, Aerospace Fluid Connector.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/section\u003e\n\n\u003chr style=\"border: 0; border-top: 1px solid #eeeeee; margin: 20px 0;\"\u003e\n\n\u003c!-- Technical Specifications --\u003e\n\u003csection class=\"koeed-specs\"\u003e\n  \u003ch3 style=\"color: #0056b3;\"\u003eTechnical Specifications\u003c\/h3\u003e\n  \u003cdiv style=\"overflow-x: auto;\"\u003e\n    \u003ctable style=\"width: 100%; border-collapse: collapse; text-align: left; font-size: 14px;\"\u003e\n      \u003cthead\u003e\n        \u003ctr style=\"background-color: #16c8c8; color: #ffffff;\"\u003e\n          \u003cth style=\"padding: 12px; border: 1px solid #eeeeee;\"\u003eParameter\u003c\/th\u003e\n          \u003cth style=\"padding: 12px; border: 1px solid #eeeeee;\"\u003eSpecification Detail\u003c\/th\u003e\n        \u003c\/tr\u003e\n      \u003c\/thead\u003e\n      \u003ctbody\u003e\n        \u003ctr style=\"background-color: #f4fcfc;\"\u003e\n          \u003ctd style=\"padding: 10px; border: 1px solid #eeeeee; font-weight: bold;\"\u003eSeries Model\u003c\/td\u003e\n          \u003ctd style=\"padding: 10px; border: 1px solid #eeeeee;\"\u003e155 Series (AERO 155-25-12D)\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr style=\"background-color: #fafafa;\"\u003e\n          \u003ctd style=\"padding: 10px; border: 1px solid #eeeeee; font-weight: bold;\"\u003eCrossover PN\u003c\/td\u003e\n          \u003ctd style=\"padding: 10px; border: 1px solid #eeeeee;\"\u003eTA155-S4-12D\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr style=\"background-color: #f4fcfc;\"\u003e\n          \u003ctd style=\"padding: 10px; border: 1px solid #eeeeee; font-weight: bold;\"\u003eBody Size\u003c\/td\u003e\n          \u003ctd style=\"padding: 10px; border: 1px solid #eeeeee;\"\u003e-12 (3\/4 Inch)\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr style=\"background-color: #fafafa;\"\u003e\n          \u003ctd style=\"padding: 10px; border: 1px solid #eeeeee; font-weight: bold;\"\u003eMaterial\u003c\/td\u003e\n          \u003ctd style=\"padding: 10px; border: 1px solid #eeeeee;\"\u003eAluminum (Anodized for Corrosion Resistance)\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr style=\"background-color: #f4fcfc;\"\u003e\n          \u003ctd style=\"padding: 10px; border: 1px solid #eeeeee; font-weight: bold;\"\u003eCoupling Style\u003c\/td\u003e\n          \u003ctd style=\"padding: 10px; border: 1px solid #eeeeee;\"\u003eThreaded Quick Disconnect \/ Self-Sealing\u003c\/td\u003e\n        \u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\u003c\/section\u003e\n\n\u003c!-- Application \u0026 Reliability --\u003e\n\u003csection class=\"koeed-application\" style=\"margin-top: 25px;\"\u003e\n  \u003ch3 style=\"color: #0056b3;\"\u003eIndustrial Reliability \u0026amp; Fluid Integrity\u003c\/h3\u003e\n  \u003cp\u003e\n    The 155 series is renowned for its \u003cstrong\u003epush-pull threaded locking mechanism\u003c\/strong\u003e, which \n    prevents accidental disconnection under high pressure or heavy mechanical load. The aluminum \n    housing offers an excellent strength-to-weight ratio, vital for weight-sensitive applications. \n    Commonly integrated into \u003cstrong\u003eclosed-loop cooling systems\u003c\/strong\u003e and \u003cstrong\u003ehigh-flow hydraulic power units\u003c\/strong\u003e, \n    this coupling assembly facilitates rapid maintenance without the need for system draining, \n    saving significant downtime in 24\/7 manufacturing or flight line operations.\n  \u003c\/p\u003e\n\u003c\/section\u003e\n\n\u003c!-- Koeed B2B Tool: Pressure \u0026 Compatibility Checker --\u003e\n\u003csection id=\"koeed-tool-section\" style=\"margin: 30px 0; padding: 25px; border: 2px solid #16c8c8; border-radius: 8px; background-color: #fff;\"\u003e\n  \u003ch3 style=\"text-align: center; color: #16c8c8; margin-top: 0;\"\u003eKoeed Interactive: Hydraulic Safety Evaluator\u003c\/h3\u003e\n  \u003cp style=\"font-size: 13px; text-align: center; color: #666;\"\u003eValidate system pressure and fluid compatibility for the AERO 155-25-12D.\u003c\/p\u003e\n  \n  \u003cdiv style=\"display: flex; flex-direction: column; gap: 15px; max-width: 500px; margin: 0 auto;\"\u003e\n    \u003cdiv\u003e\n      \u003clabel for=\"koeed-pressure\" style=\"display: block; margin-bottom: 5px; font-weight: bold;\"\u003eSystem Working Pressure (PSI):\u003c\/label\u003e\n      \u003cinput type=\"number\" id=\"koeed-pressure\" value=\"500\" style=\"width: 100%; padding: 12px; border: 1px solid #ccc; border-radius: 4px;\" aria-label=\"Enter system pressure in PSI\"\u003e\n    \u003c\/div\u003e\n    \n    \u003cdiv\u003e\n      \u003clabel for=\"koeed-fluid\" style=\"display: block; margin-bottom: 5px; font-weight: bold;\"\u003eFluid Type:\u003c\/label\u003e\n      \u003cselect id=\"koeed-fluid\" style=\"width: 100%; padding: 12px; border: 1px solid #ccc; border-radius: 4px;\" aria-label=\"Select fluid type\"\u003e\n        \u003coption value=\"standard\"\u003ePetroleum\/Mineral Oil (MIL-H-5606)\u003c\/option\u003e\n        \u003coption value=\"fuel\"\u003eJet Fuel \/ Gasoline\u003c\/option\u003e\n        \u003coption value=\"skydrol\"\u003ePhosphate Ester (Skydrol) - *Warning*\u003c\/option\u003e\n      \u003c\/select\u003e\n    \u003c\/div\u003e\n\n    \u003cbutton onclick=\"koeedAnalyzeHydraulic()\" style=\"background-color: #16c8c8; color: white; border: none; padding: 14px; cursor: pointer; border-radius: 4px; font-weight: bold; font-size: 16px;\"\u003eRun Safety Check\u003c\/button\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv id=\"koeed-calc-result\" style=\"margin-top: 20px; padding: 15px; background: #f9f9f9; border-left: 4px solid #16c8c8; display: none;\"\u003e\u003c\/div\u003e\n\n  \u003cnoscript\u003e\n    \u003cp\u003eManual Check: The AERO 155-25-12D aluminum coupling is typically rated for operating pressures up to 1000 PSI depending on fluid temp. Not compatible with Skydrol unless specifically fitted with EPR seals.\u003c\/p\u003e\n  \u003c\/noscript\u003e\n\u003c\/section\u003e\n\n\u003c!-- Troubleshooting FAQ --\u003e\n\u003csection class=\"koeed-faq\"\u003e\n  \u003ch3 style=\"color: #0056b3;\"\u003eMaintenance \u0026amp; Troubleshooting FAQ\u003c\/h3\u003e\n  \u003cdiv style=\"margin-bottom: 15px;\"\u003e\n    \u003cp\u003e\u003cstrong\u003eQ1: Fluid is weeping from the coupling joint when connected.\u003c\/strong\u003e\u003cbr\u003e\n    \u003cem\u003eA:\u003c\/em\u003e This is often caused by \u003cstrong\u003eworn O-rings\u003c\/strong\u003e or debris in the valve seat. For the 155 series, ensure the mating surfaces are clean. If weeping persists, the internal seal (typically Buna-N or Viton) may need replacement due to fluid incompatibility or thermal degradation.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv style=\"margin-bottom: 15px;\"\u003e\n    \u003cp\u003e\u003cstrong\u003eQ2: The threaded sleeve is difficult to rotate by hand.\u003c\/strong\u003e\u003cbr\u003e\n    \u003cem\u003eA:\u003c\/em\u003e High residual system pressure is the primary cause. Even with self-sealing valves, extreme back-pressure makes hand-threading difficult. Relieve system pressure or use a specialized spanner wrench on the provided flats. Lubricate threads with a compatible fluid.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv style=\"margin-bottom: 15px;\"\u003e\n    \u003cp\u003e\u003cstrong\u003eQ3: Can I swap this Aluminum unit (12D) for a Steel version?\u003c\/strong\u003e\u003cbr\u003e\n    \u003cem\u003eA:\u003c\/em\u003e Physically, yes, if the series is the same (155). However, a steel version (usually marked 'S') handles much higher pressures. Conversely, replacing steel with aluminum (12D) in a high-pressure line (above 1500 PSI) is dangerous. Always verify the 'D' suffix is correct for your application's pressure and weight requirements.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/section\u003e\n\n\u003c!-- JavaScript Logic --\u003e\n\u003cscript\u003e\nfunction koeedAnalyzeHydraulic() {\n  const pressure = parseFloat(document.getElementById('koeed-pressure').value);\n  const fluid = document.getElementById('koeed-fluid').value;\n  const resultDiv = document.getElementById('koeed-calc-result');\n  \n  resultDiv.style.display = 'block';\n  let message = \"\";\n  let color = \"#28a745\"; \/\/ Green\n\n  \/\/ Typical Aluminum 155 series -12 rating is around 1000 PSI operating\n  const maxSafePressure = 1000;\n\n  if (fluid === 'skydrol') {\n    message = \"\u003cstrong\u003eWARNING:\u003c\/strong\u003e Standard aluminum 155 units with nitrile\/viton seals are NOT compatible with Skydrol. Using this fluid will cause seal swelling and system failure. Contact FAE for EPR seal options.\";\n    color = \"#dc3545\"; \/\/ Red\n  } else if (pressure \u003e maxSafePressure) {\n    message = `\u003cstrong\u003eDANGER:\u003c\/strong\u003e The requested ${pressure} PSI exceeds the typical recommended operating pressure for aluminum -12 couplings (${maxSafePressure} PSI). High risk of thread stripping or housing rupture. Consider a Stainless Steel (S) series.`;\n    color = \"#dc3545\"; \/\/ Red\n  } else {\n    const bar = (pressure * 0.0689476).toFixed(2);\n    message = `\u003cstrong\u003eSystem OK:\u003c\/strong\u003e ${pressure} PSI (${bar} Bar) is within the safe operating range for the 155-25-12D. Your selected fluid is compatible with standard aerospace-grade aluminum seals.`;\n  }\n\n  resultDiv.innerHTML = `\u003cdiv style=\"color: ${color}; line-height: 1.5;\"\u003e${message}\u003c\/div\u003e`;\n}\n\u003c\/script\u003e\n\n\u003c!-- Structured Data --\u003e\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How to fix a leaking Aeroquip 155 coupling?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Inspect the internal seals and O-rings for debris or nicks. Ensure the threaded sleeve is fully tightened. If leaking continues, verify the fluid is compatible with the seal material (Nitrile vs. Viton).\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the difference between AERO 155-25-12D and 155-25-12S?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The 'D' suffix indicates an Aluminum construction, which is lightweight but has a lower pressure rating. The 'S' suffix indicates Steel, which is heavier but supports significantly higher working pressures.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"WebApplication\",\n  \"name\": \"Koeed Hydraulic Safety Evaluator\",\n  \"operatingSystem\": \"All\",\n  \"applicationCategory\": \"EngineeringTool\",\n  \"description\": \"Evaluates the safety and compatibility of Aeroquip 155 series couplings based on system pressure and fluid type.\"\n}\n\u003c\/script\u003e","brand":"AEROQUIP","offers":[{"title":"Default Title","offer_id":44285064085689,"sku":"224422000769","price":490.03,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0268\/8476\/7929\/files\/s-l1600_3f2a0f77-19c5-491b-a031-5fc99e769007.jpg?v=1723836090","url":"https:\/\/koeed.com\/da\/products\/new-aeroquip-a-nut-e-155-25-12d-coupling-assembly-ta155-s4-12d-a2061-a1061","provider":"KOEED","version":"1.0","type":"link"}