Rubber Bellows Mechanical Seal for Water Pumps with Temperature Range -20-150°C

Rubber Bellows Mechanical Seal Replace John Crane 2100

The Model 2100 is a rubber bellows mechanical seal designed for water pump applications. Its elastomer bellows construction provides effective compensation for shaft runout and minor misalignments. This seal configuration typically incorporates a carbon ceramic face combination, ensuring reliable performance in residential and commercial water circulation systems. The unit's compact design facilitates straightforward installation in standard pump housings, delivering durable sealing for clean water service with minimal maintenance requirements.

Operating Limited:

Material:

Advantages:

• Spring unit averted from the product so no sticking and clogging of the springs
• Safe operation (no fractures) because of seal face locking by square pin
• Suitable for pressure reversals
• Operation in vacuum without additional seat locking possible
• No damage of the shaft by a dynamically loaded O-Ring
• Small installation sizes
• Best suitable for conversions, no adaptations of the pump
• Insensitive to solid containing and abrasive media
• Advantages of a balanced seal even with plain shafts
• Insensitive to shaft movements because of the stationary design

Application:

• Water and waste water technology
• Chemical industry
• Refining technology
• Dirty, abrasive and solid containing media
• Fugitive hydrocarbons (no API seal!)
• Sticky and stringy media
• Chemical standard pumps
• Sewage pumps

Shipping & Payment Terms:

Port of Loading: Shanghai

Shipping Method: DHL,UPS,FEDEX,TNT, etc

Payment Terms: T/T, Western Union, money gram

Our services:

• OEM/ODM orders are available for our factory
• Accept customized mechanical seals according to your drawing or requirements
• Small quantity is accepted
• Provides excellent quality with competitive price

Q&A:

Q1: What is the primary functional advantage of the rubber bellows in the Model 2100?
A1: The elastomeric bellows serves as a dynamic sealing element that compensates for axial shaft movement, minor shaft misalignment, and face wear. Its flexibility provides superior vibration damping compared to rigid pusher-type seals, making it ideal for applications in smaller, high-RPM motors.

Q2: For which specific pump types is the Model 2100 typically specified?
A2: This seal is predominantly engineered for use in light-duty centrifugal pumps. Common applications include domestic water circulation pumps, automotive coolant pumps, and various OEM equipment pumps handling non-aggressive, clear liquids.

Q3: What are the standard face material pairs available for the Model 2100, and how are they selected?
A3: The standard configuration typically features a carbon primary face running against a ceramic stationary face. This combination provides excellent dry-running tolerance and reliable performance for water-based fluids. For extended service life in slightly abrasive or higher-temperature water, an upgrade to a silicon carbide stationary face is often recommended.

Q4: How does the Model 2100's performance compare to a pusher-type seal in a water pump application?
A4: In clean water service, the Model 2100's bellows design offers a distinct advantage by eliminating the hang-up risk associated with pusher seal auxiliary components (like O-rings or PTFE wedges) that can stick in their bore. This results in more consistent face loading and reliable sealing in applications where mineral deposit formation is a concern.

Q5: What is the most critical factor during the installation of this seal to prevent premature failure?
A5: The most critical step is ensuring the sealing faces remain completely free of contamination. Even microscopic particles introduced during handling can score the finely polished faces. Additionally, the bellows must be seated squarely on the shaft without any twisting or rolling, which can create a leak path and impede its ability to flex.

Q6: What chemical compatibility issues should be considered with the rubber bellows?
A6: The standard bellows elastomer is typically Nitrile (NBR), which is suitable for water and glycol-based coolants within its temperature range. However, exposure to chlorinated water, ozone, or certain aliphatic solvents can cause the elastomer to harden and crack, leading to catastrophic failure. For such media, specifying a bellows made of EPDM or FKM (Viton) is essential.

Q7: Can the Model 2100 be used in a dual-purpose coolant/air conditioning pump?
A7: While it may function, this is not generally recommended without verification. Refrigerant compatibility with the standard NBR bellows is poor, and the lubricity of the fluid differs significantly from water. A seal specifically engineered for A/C compressor duty, often with an HNBR or FKM bellows, should be used for that application.

Q8: What are the tell-tale signs of a failing Model 2100 seal during operation?
A8: Initial failure often presents as a fine, barely visible mist or persistent dampness around the seal gland. As degradation progresses, this advances to a steady drip. In advanced stages, coolant contamination or audible squealing from the faces may occur, indicating significant face damage or bellows hardening.