{"product_id":"air-flow-products-840-1-ratd20-000004-stick-on-takeoff-with-damper","title":"Air Flow Products 840-1-RATD20-000004 Stick-on Takeoff with Damper","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe AIR FLOW PRODUCTS 840-1-RATD20-000004 is an airtight stick-on takeoff fitting designed for round duct pipe installations that require a built-in volume damper. The fitting attaches directly to the trunk line using an adhesive-backed collar, eliminating the need to cut and collar traditional sheet metal. At 4 inches in diameter with a 2-inch standoff, it provides a compact, low-profile branch connection suited for residential and light commercial forced-air duct systems. The integrated damper allows airflow balancing at the takeoff point without adding a separate damper assembly. HVAC sheet metal mechanics and duct installers are the primary trades working with this fitting.\u003c\/p\u003e\n\u003cp\u003eThis takeoff is used in residential and light commercial HVAC duct systems where round branch runs are tapped off a rectangular or round main trunk. The stick-on design is particularly useful in retrofit and repair scenarios where cutting into an existing trunk line is impractical or where a faster installation method is preferred. The 2-inch standoff positions the branch outlet away from the trunk surface, making flex duct or rigid pipe connection straightforward in tight plenum and attic spaces.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eAirtight adhesive collar mounts directly to trunk line surface without cutting a traditional collar hole\u003c\/li\u003e\n  \u003cli\u003eIntegrated volume damper allows airflow balancing at the branch takeoff point\u003c\/li\u003e\n  \u003cli\u003e4-inch round outlet diameter for standard branch duct connections\u003c\/li\u003e\n  \u003cli\u003e2-inch standoff keeps the branch outlet clear of the trunk surface for easier duct attachment\u003c\/li\u003e\n  \u003cli\u003eDesigned for airtight duct construction to reduce conditioned air loss\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style replacement and new-installation fitting for 4-inch round branch takeoffs on rectangular or round trunk duct systems in residential and light commercial forced-air HVAC applications.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation is typically performed by a licensed HVAC technician or sheet metal mechanic. Power down the air handling unit and confirm the system is de-energized before working inside the plenum or on active duct runs. The adhesive collar surface and trunk duct surface should be clean and dry before bonding for a reliable airtight seal. Local energy codes and ACCA Manual D duct design standards may govern takeoff placement and airflow balancing requirements.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOutlet Diameter\u003c\/strong\u003e: 4 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStandoff Height\u003c\/strong\u003e: 2 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDamper\u003c\/strong\u003e: Integrated volume damper\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMount Type\u003c\/strong\u003e: Stick-on adhesive collar\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDuct Type\u003c\/strong\u003e: Round pipe\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSeal Type\u003c\/strong\u003e: Airtight\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eStandard Information\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: AIR FLOW PRODUCTS\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 840-1-RATD20-000004\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"AIR FLOW PRODUCTS","offers":[{"title":"Default Title","offer_id":51344310698290,"sku":"840-1-RATD20-000004","price":30.06,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310553250.jpg?v=1782033072","url":"https:\/\/voomisupply.com\/products\/air-flow-products-840-1-ratd20-000004-stick-on-takeoff-with-damper","provider":"Voomi Supply","version":"1.0","type":"link"}