Grundfos mechanical pump shaft seals replacement is engineered as a direct-fit, OEM-compatible solution for Grundfos CR, CM, SP, NB, and other series pumps. Manufactured by MIAOYU, these seals are precision-matched to original specifications for shaft diameters (12mm, 16mm, 22mm, etc.), ensuring reliable leak-free performance in water supply, HVAC, and chemical applications. Available in cartridge or semi-cartridge designs with material upgrades (SiC, TC, Viton), they offer easy installation and extended service life, providing a cost-effective alternative to genuine parts while maintaining high durability and interchangeability standards.
Key Features
• Universal Replacement: A comprehensive range of O-ring and Bellows seals to replace standard Grundfos "Type A" (O-ring) and "Type B" (Bellows) seals.
• Fits TP, NB, NK Series: Mechanical pump shaft seals are designed for the widely used Grundfos end-suction and inline circulating pumps found in HVAC and water utility systems.
• Metric Precision: Manufactured to exact DIN standard dimensions (12mm to 38mm+ shafts) to ensure a leak-free fit in the pump backplate.
• Torque Lock System: Features the specific drive notch or grub screw arrangement required by Grundfos shafts to prevent seal slippage.
• Flexible Material Options: Mechanical pump shaft seals are available in various combinations (Carbon/Ceramic/EPDM for cost, SiC/SiC/FKM for durability) to suit any budget or fluid.
Technical Specs | Materials | ||
Mediums | Water, oil and weakly-corrosive mediums | Stationary Ring | Carbon/Sic |
Pressure | ≤0.3MPa | Rotary Ring | Ceramic/Sic |
Temperature | -20℃ to 100℃ | Secondary Seal | NBR/EPDM/Viton |
Speed | ≤10m/s | Spring and Metal Part | Stainless Steel |
Product Specifications
| Model | Shaft | D2 | D3 | D7 | L1 | L2 | L4 |
| 10 | 10 | 24.0 | 29.0 | 23.0 | 7.0 | 6.0 | 4.0 |
| 12S | 12 | 28.6 | 32.0 | 25.0 | 8.0 | 5.2 | 5.0 |
| 12M | 12 | 30.0 | 35.0 | 24.0 | 8.0 | 5.0 | 5.0 |
| 12L | 12 | 33.4 | 38.0 | 25.0 | 6.7 | 6.3 | 5.0 |
| 16 | 16 | 36.5 | 41.5 | 31.0 | 8.0 | 6.8 | 5.0 |
| 16L | 16 | 38.1 | 43.5 | 31.0 | 8.0 | 6.8 | 5.0 |
| 16LD | 16 | 38.1 | 43.5 | 31.0 | 8.0 | 6.8 | 5.0 |
| 20S | 20 | 38.0 | 43.8 | 35.0 | 9.5 | 6.0 | 5.0 |
| 20 | 20 | 40.0 | 43.8 | 35.0 | 9.5 | 6.0 | 5.0 |
| 25S | 25 | 46.0 | 51.0 | 44.0 | 10.0 | 8.0 | 7.0 |
| 25M | 25 | 47.0 | 51.0 | 44.0 | 12.0 | 6.0 | 7.0 |
| 25L | 25 | 52.0 | 57.0 | 48.0 | 12.0 | 6.0 | 7.0 |
| 30 | 30 | 52.0 | 57.0 | 48.0 | 11.0 | 8.0 | 8.0 |
| 1/2" | 12.7 | 30.0 | 35.0 | 25.4 | 8.0 | 5.0 | 6.2 |
| 5/8" | 25.9 | 36.5 | 41.5 | 31.8 | 8.0 | 6.7 | 10.3 |
| 3/4" | 19.1 | 40.0 | 43.8 | 34.9 | 9.5 | 6.0 | 10.3 |
| 1" | 25.4 | 47.0 | 51.0 | 41.3 | 12.0 | 5.9 | 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 mechanical pump shaft seals 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
Facility Management: A university campus needed to service 50 various Grundfos heating pumps. We supplied a mix of Type A and Type B replacements. The compatibility was 100%, and the project came in 40% under budget compared to OEM parts.
Testimonials
A great one-stop solution for our mixed fleet of Grundfos pumps. The quality is consistent and delivery is fast.
—Procurement Officer, HVAC Services
FAQs about Grundfos Mechanical Pump Shaft Seals Replacement
Q: What is the difference between Type A and Type B?
A: Type A is an O-ring seal with a fixed driver. Type B is a rubber bellows seal. You must check your old seal visual style or pump code (e.g., BAQE vs BBQE) to choose the correct replacement.
Q: Which Grundfos pump models are these shaft seals compatible with?
A: Our replacement mechanical pump shaft seals are engineered for direct interchangeability with popular Grundfos series including CR, CRE, CRN, CRI, CM, SP, NB, and submersible pumps. They support standard shaft diameters (12mm, 16mm, 22mm, 32mm). For exact matching, please provide your pump model number and shaft size.
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
