Castair Rubber Cushion Base Mount 100mm Heavy Duty (RCBM100HU)
The Castair RCBM100HU is a 100mm heavy-duty (HU) rubber cushion base mount for air compressor installations. The heavy-duty designation indicates a higher load rating compared to the standard double-cup RCBM100DC, making it appropriate for heavier compressor frames, larger motor weights, or installations where the mount must support more concentrated load at each foot location. Both are 100mm diameter — the HU version uses a different rubber compound or geometry to handle greater compressive loads without bottoming out.
Specific load ratings, deflection curves, and bolt patterns for the RCBM100HU were not published on castair.net at time of writing. Call us at 866-217-0063 with your compressor model and weight to confirm whether the DC or HU designation is appropriate for your application.
Mount Specifications
- Part number: RCBM100HU
- Diameter: 100mm
- Configuration: Heavy Duty (HU)
- Material: Heavy-duty rubber bonded to steel
- Application: Air compressor vibration isolation — heavier compressor frames
- Load rating: Contact 866-217-0063 for confirmed load specifications
RCBM Mount Size and Rating Comparison
- RCBM100DC: 100mm, double-cup — standard load rating
- RCBM100HU (this part): 100mm, heavy-duty — higher load capacity
- RCBM140DC: 140mm, double-cup — larger footprint, standard load
- RCBM140HU: 140mm, heavy-duty — largest and highest rated in the RCBM series
Castair's standard flat vibration pads (VP100, 4"x4"x1", or VP1004 set of 4) are appropriate for most piston compressor installations. The RCBM cup-style mounts provide more engineered isolation for larger rotary screw units or equipment with higher vibration loads.
Why Proper Vibration Isolation Matters
- Continuous-duty operation: Rotary screw compressors run 100% duty — they never stop vibrating while running. The mount must handle sustained load, not just occasional use
- Structure protection: Vibration conducted into concrete floors and building structures causes long-term fatigue damage. Proper isolation is part of a correct installation
- Pipe and fitting protection: A compressor properly isolated on vibration mounts requires flex hose at the discharge connection — the small amount of movement allowed by the mounts will otherwise crack rigid piping connections over time
- Acoustic isolation: Heavy-duty mounts reduce low-frequency vibration transmission into floors and walls more effectively than lighter mounts that are undersized for the load
Installation Notes
- Typically 4 mounts per compressor installation, one per base foot
- Match mount rating to the load — over-rated mounts do not dampen as well as properly loaded mounts
- Use with metal flex hose at discharge connection to allow the mounts to function correctly
What Is in the Box
- 1x Castair RCBM100HU rubber cushion base mount, 100mm heavy-duty configuration
Why Buy From Air Compressor Factory Direct?
- Castair authorized: OEM vibration mounts for Castair compressor installations
- Free shipping on qualifying orders
- Free tech support: 866-217-0063 — help selecting DC vs. HU and 100mm vs. 140mm for your specific compressor
- Full accessory lineup: Flex hose, ball valves, mounts, and installation kits
Call 866-217-0063 for quick answers and help!
