{"product_id":"castair-replacement-oil-filter-element-rofd3-4-g11","title":"Castair Replacement Oil Filter Element - ROFD3-4-G11","description":"\u003cp\u003eThe \u003cstrong\u003eCastair ROFD3-4-G11\u003c\/strong\u003e is the OEM spin-on oil filter for Castair rotary screw compressors equipped with the \u003cstrong\u003eD3, D31, D4, or G11 air end\u003c\/strong\u003e. These air ends are found in Castair's 5–15 HP rotary screw models — the smaller end of their rotary lineup, but still 100% duty cycle machines that demand proper lubrication maintenance. One filter part number covers all four of these air ends, simplifying what you need to stock. If your Castair rotary compressor is in the 5–15 HP range and uses a D3, D31, D4, or G11 air end, this is your oil filter.\u003c\/p\u003e\n\n\u003ch2\u003eAir End Coverage\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eD3 \/ D31 air end:\u003c\/strong\u003e Used in 5–10 HP Castair rotary screw models. The D31 is a variant of the D3 used in certain configurations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eD4 air end:\u003c\/strong\u003e Used in 5–10 HP Castair rotary screw models.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eG11 air end:\u003c\/strong\u003e Used in 5–15 HP Castair rotary screw models.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eCheck your compressor's model designation or service documentation to confirm which air end your unit carries. The oil filter part number is identical across all four, so if you have any of these air ends, the ROFD3-4-G11 is correct.\u003c\/p\u003e\n\n\u003ch2\u003eWhy Oil Filtration Matters at 5–15 HP\u003c\/h2\u003e\n\u003cp\u003eSmaller rotary compressors often run at higher utilization rates relative to their size — a 7.5 HP rotary in a two-bay shop may run more total hours per day than a 30 HP unit in a larger facility. Continuous operation at high utilization means the oil circuit handles more thermal cycles, more particulate accumulation, and more opportunity for water contamination from air cooling. The ROFD3-4-G11 filter is your primary defense against particulate damage to the rotor bearings and timing gears in these air ends.\u003c\/p\u003e\n\n\u003ch2\u003eMaintenance Context\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilter type:\u003c\/strong\u003e Spin-on, automotive-style paper element\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaintenance kits:\u003c\/strong\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMKD3-4\u003c\/strong\u003e — for D3, D31, D4 air ends: 2 air filters (RAFD3-4), 4 oil filters (this part), 1 separator filter (RSFD3-4-6-G11-P75), 5 gallons synthetic oil — 10% savings\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMKG11\u003c\/strong\u003e — for G11 air ends: 2 air filters (RAFG11), 4 oil filters (this part), 1 separator filter (RSFD3-4-6-G11-P75), 5 gallons synthetic oil — 10% savings\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil:\u003c\/strong\u003e GA4000 or FG4000 Castair synthetic rotary screw oil (1 year\/4,000 hours)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eService interval:\u003c\/strong\u003e Replace with each oil change per Castair maintenance schedule; use the standard hour meter to track\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e ROFD3-4-G11\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilter Type:\u003c\/strong\u003e Spin-on oil filter\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Air Ends:\u003c\/strong\u003e Castair D3, D31, D4, G11\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Compressor HP:\u003c\/strong\u003e 5–15 HP rotary screw models\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Cast Air\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy Buy From OEM Diagnostic Tools?\u003c\/h3\u003e\n\u003cp\u003eGenuine Castair OEM maintenance filters — not aftermarket substitutes. Free shipping on qualifying orders. Free tech support at \u003cstrong\u003e866-217-0063\u003c\/strong\u003e. Full Castair manufacturer warranty. Call us to confirm the correct filter for your specific air end.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCall 866-217-0063 for quick answers and help!\u003c\/strong\u003e\u003c\/p\u003e","brand":"Cast Air","offers":[{"title":"Default Title","offer_id":53342596104405,"sku":"ROFD3-4-G11","price":93.72,"currency_code":"USD","in_stock":true}],"url":"https:\/\/aircompressorfactorydirect.com\/products\/castair-replacement-oil-filter-element-rofd3-4-g11","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}