• Self-Adjusting: The single coil spring and O-ring mount allow the seal to adjust automatically to shaft end-play and runout.
• Field Repairable: The modular component design allows for easy replacement of faces or elastomers if the metal parts are still serviceable.
Key Features
• The Industry Standard: The definitive Pac-Seal Type 21 is the world's most common general-purpose mechanical seal. Our aftermarket replacement matches it perfectly.
• Drive Band Transmission: Features the classic "dent and groove" drive band that mechanically locks the spring to the rotary face holder, preventing slippage.
• Compact & Low Cost: A simple, effective solution for OEM pumps, mixers, and water systems where space and budget are limited.
Technical Specs | Materials | ||
Mediums | Water, oil and weakly-corrosive mediums | Stationary Ring | Ceramic/Sic/TC |
Pressure | ≤0.5MPa | Rotary Ring | Carbon/Sic/TC |
Temperature | -20℃ to 100℃ | Secondary Seal | NBR/EPDM/Viton |
Speed | ≤10m/s | Spring and Metal Part | Stainless Steel |
Product Specifications
| D1 (inch) | Size Code | D3 | D7 | L1 | L4 |
| 0.375 | 0095 | 23.8 | 22.23 | 16.08 | 6.35 |
| 0.375A | 0095A | 26.97 | 25.4 | 16.86 | 7.93 |
| 0.500 | 0127 | 26.97 | 25.4 | 16.86 | 6.35 |
| 0.500A | 0127A | 26.97 | 25.4 | 16.86 | 7.93 |
| 0.625 | 0158 | 30.94 | 31.75 | 18.44 | 10.31 |
| 0.750 | 0191 | 34.11 | 34.93 | 18.44 | 10.31 |
| 0.875 | 0222 | 42.85 | 41.28 | 20.82 | 11.1 |
| 1.000 | 0254 | 42.85 | 41.28 | 20.82 | 11.1 |
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
Commercial Irrigation: An irrigation contractor switched to our Type 21 replacements for their pump repairs. The robust drive band handled the torque of frequent start-stops better than cheaper clones, reducing warranty calls.
Testimonials
We buy these by the hundreds. They fit every Goulds and Griswold pump we service. Reliable and cheap.
—Pump Distributor, California
FAQs about Metal Bellows Seals for High Temperature Pumps
Q: Is this compatible with John Crane Type 21?
A: Yes, the Flowserve Pac-Seal 21 and John Crane Type 21 are functionally identical. Our seal replaces both brands seamlessly.
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
