{"product_id":"castair-base-mount-top-plate-12-5x32-bm12-5x32","title":"Castair Base Mount Top Plate 12.5x32 - BM12.5x32","description":"\u003cp\u003eThe Castair BM12.5x32 is a bare base plate measuring 12.5 inches by 32 inches by 3\/16-inch steel — the mounting surface that sits on top of a vertical air compressor tank and supports the pump, motor, and associated drive components. This is a structural part. It is what the compressor assembly rests on, and when it corrodes through or cracks under vibration fatigue, the entire pump-motor assembly needs a replacement plate before it can run safely.\u003c\/p\u003e\n\n\u003cp\u003eCastair lists this part as BP125x32 on their site — BM12.5x32 is the SKU used in this catalog. Same part, same dimensions. The 3\/16\" steel construction is appropriate for the mid-range tank sizes this plate is used with.\u003c\/p\u003e\n\n\u003ch3\u003eWhat a Base Plate Does and Why It Matters\u003c\/h3\u003e\n\u003cp\u003eOn a vertical tank-mounted reciprocating compressor, the pump and motor do not sit directly on the tank dome. They sit on a flat steel plate that spans the top of the tank — the base plate. That plate does several things at once:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDistributes load:\u003c\/strong\u003e Spreads the combined weight of the pump, motor, flywheel, and pulley system across the tank top rather than concentrating it at mounting points\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAbsorbs vibration:\u003c\/strong\u003e Acts as the primary structural interface between the running compressor and the tank — reciprocating compressors generate significant cyclic vibration loads during operation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProvides mounting surfaces:\u003c\/strong\u003e Motor and pump mounting feet bolt to the plate — the plate must be flat and structurally sound for proper alignment of the drive belt and pulley system\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eResists corrosion:\u003c\/strong\u003e The plate is exposed to both the shop environment and heat from the motor — when corrosion compromises plate thickness, structural integrity follows\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eA cracked or severely corroded base plate is not a cosmetic issue. Belt and pulley alignment depends on the plate being flat. Motor mounting depends on the plate being structurally intact. If the plate fails, the compressor cannot run safely.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSKU:\u003c\/strong\u003e BM12.5x32 (also listed as BP125x32 by Castair)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 12.5\" x 32\"\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThickness:\u003c\/strong\u003e 3\/16\" steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComponent Type:\u003c\/strong\u003e Bare base plate \/ base mount top plate\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Major Components — Tanks\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Cast Air (Castair)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAssociated Tank Size:\u003c\/strong\u003e Mid-size vertical tanks (the 80-gallon vertical tank 80V200 uses this plate size)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eConstruction Details\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e3\/16\" steel plate:\u003c\/strong\u003e Appropriate thickness for the mid-range tank sizes and compressor assemblies this plate supports — not as heavy as the 1\/4\" plates used on larger configurations, but correctly rated for this application\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBare plate:\u003c\/strong\u003e Shipped without holes or mounting hardware — drilled to match your specific motor and pump foot pattern in the field. This is standard for replacement base plates; it allows fitment across multiple compressor configurations using the same plate blank\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlat stock:\u003c\/strong\u003e Precision-flat for accurate belt drive alignment when motor and pump are mounted\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eInstallation Notes\u003c\/h3\u003e\n\u003cp\u003eThis is a bare plate. You will need to drill mounting holes to match your motor and pump foot pattern. Before drilling:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eTransfer the hole pattern from the original plate if it is still intact, or measure directly from the motor and pump mounting feet\u003c\/li\u003e\n\u003cli\u003eConfirm pulley and belt alignment after mounting — the plate must be flat and the motor-to-pump center distance must match the belt and pulley specification\u003c\/li\u003e\n\u003cli\u003eIf the original plate had rubber isolation mounts between the plate and tank saddle, reinstall those with the new plate\u003c\/li\u003e\n\u003cli\u003eCheck the tank top flange or saddle for corrosion before installing the new plate — a corroded saddle will compromise the new plate prematurely\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf you are not certain about the hole pattern or mounting configuration for your specific compressor, call us at 866-217-0063. We can often look up the original build configuration if you have the compressor model number.\u003c\/p\u003e\n\n\u003ch3\u003eAvailable Configurations — Castair Bare Base Plate Lineup\u003c\/h3\u003e\n\u003cp\u003eCastair produces bare base plates in several sizes to cover different tank and compressor combinations. Match the plate dimensions to your existing base mount — measure the old plate or refer to your compressor documentation.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBP9.5x25:\u003c\/strong\u003e 9.5\" x 25\" — for smaller vertical tanks and compressor assemblies\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBP125x32 (BM12.5x32):\u003c\/strong\u003e 12.5\" x 32\" x 3\/16\" steel — mid-size tanks, including the 80-gallon vertical (80V200) series (this part)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBP13X40:\u003c\/strong\u003e 13\" x 40\" x 1\/4\" steel — for larger tanks requiring greater plate area and heavier steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBP17x44:\u003c\/strong\u003e 17\" x 44\" x 1\/4\" steel — for the largest Castair vertical tank configurations\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf you are not certain which plate size your compressor uses, measure the existing plate — length and width — before ordering. The three larger plates (BP125x32, BP13X40, BP17x44) are all 1\/4\" or 3\/16\" steel; do not substitute a lighter plate for one of the larger sizes. Call 866-217-0063 if you need help confirming the correct size.\u003c\/p\u003e\n\n\u003ch3\u003eWhen Do You Need to Replace a Base Plate?\u003c\/h3\u003e\n\u003cp\u003eBase plates do not fail often, but when they do, the problem is usually one of three things:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRust-through:\u003c\/strong\u003e The plate has corroded from underneath — often from condensation between the plate and tank top, or from shop floor moisture in the area around the tank. A plate that has rusted through has lost structural thickness and needs replacement, not patching.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCracking:\u003c\/strong\u003e Cyclic vibration from years of reciprocating compressor operation can fatigue weld points or the plate itself, particularly around motor mounting holes. Cracks in a structural compressor plate are not a weld-and-run repair — replace the plate.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCollision or impact damage:\u003c\/strong\u003e A compressor that has been tipped or dropped may have a bent or cracked base plate even if the pump and motor appear undamaged. Check the plate for flatness before reassembling.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eA warped or compromised base plate will misalign the motor and pump, causing accelerated belt wear, bearing wear, and vibration. The plate is inexpensive relative to the pump and motor — replace it when it is compromised.\u003c\/p\u003e\n\n\u003ch3\u003eWhy Buy From Air Compressor Factory Direct?\u003c\/h3\u003e\n\u003cp\u003eWe have been specializing in air compressor parts and structural components since 2016. We stock Castair base plates across the full size range and can help you confirm which plate your compressor uses before you order. You do not need to guess based on a part number — give us the compressor model and we will look up the correct base mount specification.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree shipping\u003c\/strong\u003e on qualifying orders\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree technical support\u003c\/strong\u003e at 866-217-0063 — we confirm the right plate size and help you identify the correct hole pattern for your compressor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull manufacturer warranty\u003c\/strong\u003e on all Castair structural components\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHonest guidance\u003c\/strong\u003e — if you need a different plate size, we will tell you before you place the order\u003c\/li\u003e\n\u003c\/ul\u003e\n\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":53342520639701,"sku":"BM12.5x32","price":374.88,"currency_code":"USD","in_stock":true}],"url":"https:\/\/aircompressorfactorydirect.com\/products\/castair-base-mount-top-plate-12-5x32-bm12-5x32","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}