Rubber Bellows RBT-11 – Flexible Industrial Seal for Pumps & Valves
Rubber Bellows RBT-11 – Flexible Industrial Seal for Pumps & Valves
Overview
The RBT-11 is designed with a parallel single spring and is supplied with a rubber bellows and friction-drive collar which engages with the shaft to provide rotational movement to the seal faces.
The seal has a number of design features including a monolithic seal face and is supplied with a stationary seat as standard, and is dimensionally equivalent to the Burgmann MG1.
Product Description
Technical Specifications
| Seal Shaft Sizes | 0.47” – 2.17” |
| Inboard Seal Face Combination | Car/SiC, Car/Cer, SiC/SiC |
| Bellows | EPDM |
| Shaft Speeds | Up to 10 m/s |
| Pressures | Up to 10 barg (145 psig) – Shaft Size Specific |
Typical Applications & Industry Use Cases
The RBT-11 is a rugged rubber-bellows mechanical seal designed for light- to medium-duty rotating equipment. Its elastomer bellows offers high flexibility and an excellent ability to compensate for shaft movement, vibration, or misalignment, making it well-suited for general-purpose fluid services where elastomer compatibility and cost-effective sealing are priorities. This design is ideal for pumps and rotating machinery handling clean to moderately clean fluids.
Industries Served
Water and utility systems
service water circulation, booster pumps, and clean water applications.
General industrial fluid transfer
utility pumps, circulation systems, and auxiliary equipment handling non-aggressive liquids.
HVAC and building services
chilled water, hot water, and facility fluid circulation systems.
Light chemical services
where fluid chemistry is compatible with the rubber bellows and service is within moderate pressure/temperature limits.
OEM and retrofit applications
for pumps requiring simple, reliable sealing with minimal maintenance or complexity.
Equipment & Use-Case Scenarios
- Centrifugal and end-suction pumps where fluid is clean or lightly contaminated and sealing requirements are moderate.
- Services where pump shafts experience slight misalignment or vibration — the bellows design helps absorb movement while maintaining sealing integrity.
- Systems with restricted stuffing-box or gland spaces require a compact, flexible seal.
- Applications where ease of installation and low maintenance overhead are important for overall reliability and reduced downtime.
Why It Fits These Applications
- The elastomer bellows design provides compliance to shaft movement and compensates for axial and radial misalignment.
- Bellows reduce or eliminate the need for sliding elastomeric secondary seals, lowering the risk of leakage in vibrating or dynamic applications.
- Compact and straightforward design simplifies installation and replacement, making it ideal for maintenance teams operating in tight service windows.
- Rubber bellows offer good sealing performance for clean and moderately clean fluids at moderate pressures and temperatures, making RBT-11 a practical and reliable choice for many general-duty applications.
Installation Guidelines
Inspect mating surfaces
Ensure that the pump shaft, seal chamber bore (or gland face), and shaft sleeve are smooth, free of corrosion, scoring, and debris before installation. Clean, smooth surfaces help maintain long service life.
Mount the bellows seal carefully
When sliding the seal into place, avoid twisting or stretching the elastomer bellows. Proper orientation and a relaxed bellows condition ensure correct sealing performance.
Lubricate sealing surfaces lightly
Apply a thin compatible lubricant to the elastomer surfaces before installation to ease assembly and protect the bellows and sealing faces.
Check alignment and clamp
Tighten gland clamps evenly to avoid face misalignment. Confirm that shaft alignment and surface finish are within acceptable tolerances before commissioning.
Maintenance & Inspection Best Practices
-
Regular inspections
During scheduled maintenance, inspect the bellows for signs of hardening, cracking, swelling, or degradation due to chemical exposure or heat. -
Check seal faces
Evaluate the condition of seal faces during shutdowns — look for wear, scoring, chipping, or deposits that could impair sealing. -
Monitor operating conditions
Track pump vibration, noise, and temperature around the seal area. Excessive vibration or alignment issues accelerate bellows fatigue and shorten seal life. -
Maintain fluid cleanliness
Even in clean services, particulate contamination can accelerate wear; upstream filtration or screens help protect sealing surfaces. -
Proactively replace
worn bellows, faces, or sealing elements before failure to prevent unplanned downtime and protect pump internals.
Service & Support Options
-
Pre-installation review
Confirm that fluid chemistry, pressure, temperature, and shaft alignment are within the RBT-11 seal’s elastomer and design limits. -
Spare parts stocking
Keep bellows, seal faces, and elastomer kits on hand to enable rapid maintenance turnaround. -
Commissioning assistance
Guidance on proper installation, alignment, and leak-free startup helps ensure optimal performance from the beginning. -
Preventive maintenance scheduling
Establish periodic inspection intervals and part replacement plans to extend the mean time between maintenance actions and reduce unplanned failures. -
Upgrade guidance
If service conditions intensify (higher pressure, abrasive or aggressive fluid, elevated temperature), consider evaluating more robust seal alternatives (multi-spring, cartridge, bellows with resistant materials, or dual seals) to meet new requirements.
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Contact HydroMax Seal
Contact HydroMax Seal today for innovative solutions, expert guidance, and over a century of engineering excellence. Your journey to mechanical sealing excellence starts with HydroMax Seal!
E-Mail: sales@hydromaxseal.com
Address: 18511 Beaumont Hwy Building D
Houston, TX
77049
