• Torque Handling: The drive band transmits torque from the spring to the face more reliably than friction-drive seals, making it suitable for higher viscosity fluids.
• Field Repairable: The simple component design allows for easy field replacement of worn faces or O-rings if the metal parts are still good.
Key Features
• Direct Replacement: A precise aftermarket replacement for the Flowserve Pac-Seal Type 21, matching fit, form, and function perfectly.
• General Purpose Workhorse: The Type 21 is the industry standard for general-purpose centrifugal pumps, mixers, and compressors.
• Unique Drive Band: Features the signature "dent and groove" drive band design that mechanically locks the spring and seal face, preventing slippage.
Product Specifications
| Pump Ref: | Metric Shaft D1 | Size Code | D3 | D7 | L1 | L4 |
| SR1 | 20.0 | 0200 | 31.0 | 30.0 | 19.1 | 10.7 |
| SR2 | 30.0 | 0300 | 41.0 | 41.3 | 19.1 | 10.9 |
| SR3 | 35.0 | 0350 | 45.5 | 47.0 | 19.1 | 12.2 |
| SR4 | 45.0 | 0450 | 58.2 | 58.3 | 21.1 | 11.6 |
| SR5 | 55.0 | 0550 | 72.0 | 69.6 | 22.1 | 13.0 |
| SR6 | 75.0 | 0750 | 96.0 | 92.2 | 25.8 | 14.5 |
Workshop
This workshop is equipped with professional processing equipment and integrated with standardized material warehousing management, enabling a one-stop production process from precision machining to finished product delivery. It ensures part machining accuracy and production efficiency, meeting various high-specification manufacturing requirements.
Product Research, Development and Testing
Our Product R&D and Testing focuses on optimizing seal performance through advanced simulation and material analysis. All seals undergo rigorous trials, including thermal cycling and pressure tests, to ensure durability, minimal leakage, and long service life in demanding industrial environments.
Industry Solutions
Case Study
Water Park Pumps: A large water park needed to replace seals on dozens of circulation pumps. The OEM lead time was too long. We supplied our Type 21 Replacement in bulk. They fit perfectly and handled the chlorinated water without issue.
Testimonials
We buy these Type 21s by the hundreds. They fit all our Flowserve and Goulds pumps and cost half the price of the OEM box.
—Pump Repair Shop Owner, Florida
FAQs about Metal Bellows Seals for High Temperature Pumps
Q: Is this the same as John Crane Type 21?
A: Yes, the Flowserve Pac-Seal Type 21 and John Crane Type 21 are functionally identical industry standards. Our replacement fits pumps designed for either brand.
Our company is specialized in the production of sealing materials, mechanical seals , cartridge seals.
E-mail: gechacha@aliyun.com
Mobile: +86-18758835650
WhatsApp: +86-18758835650
Add: No8-2, Jinsha road Yuelin Street, Fenghua District, Ningbo, Zhejiang
