Our metal bellows mechanical seal is available in standard small shaft sizes including 12mm mechanical seal, 14mm mechanical seal, 16mm mechanical seal, and 18mm mechanical seal configurations. The all-welded metal bellows design eliminates dynamic O-ring hang-up, making it suitable for hot water, light hydrocarbon, and chemical services on small centrifugal pumps and lab-scale mixers. Each size follows ISO envelope dimensions for direct OEM replacement. Custom face materials (SiC/TC/Carbon) and elastomers (Viton®/EPDM/Kalrez®) are available.
Key Features
• Miniature Precision: High-performance metal bellows mechanical seal technology scaled down for small-diameter shafts (12mm to 18mm), delivering premium reliability for compact pumps, gearboxes, and micro-mixers.
• Space-Saving: Extremely short working length fits into tight micro-pump housings where standard seals won't fit. Ideal for 12mm, 14mm, 16mm, and 18mm mechanical seal installations with limited axial space.
• Pure Construction: No glue or adhesives; fully welded metal structure ensures chemical purity and temperature resistance up to 400°C. Essential for food-grade, pharmaceutical, and ultra-pure water applications.
• Micro-Welding Technology: We utilize advanced laser micro-welding to fabricate these small bellows with consistent spring rates and high flexibility, ensuring each 12mm to 18mm mechanical seal meets precise performance specs.
• Direct Shaft Fit: Designed to fit standard metric tolerance shafts directly without complex sleeves or adapters. Each metal bellows mechanical seal ships ready for drop-in installation.
Technical Specs | Materials | ||
Mediums | Oil, light hydrocarbon, aromatic hydrocarbon, organic solvents, weak acids, alkali, Ammonia, etc. | Stationary Ring | Sic/TC |
Temperature | -75℃ to 400℃ | Rotary Ring | Carbon/Sic/TC |
Pressure | ≤2.0MPa (Single), ≤6.0MPa (Double) | Secondary Seal | Graphite |
Speed | ≤23m/s | Spring and Metal Part | Stainless Steel |
Product Specifications
| Size/inch D1 | Size Code | D3 | L1 |
| 1.000 | 0254 | 41.28 | 38.89 |
| 1.125 | 0286 | 44.45 | 39.67 |
| 1.250 | 0317 | 47.63 | 40.46 |
| 1.375 | 0349 | 50.80 | 40.46 |
| 1.500 | 0381 | 53.98 | 40.46 |
| 1.625 | 0412 | 57.15 | 40.46 |
| 1.750 | 0444 | 60.33 | 41.28 |
| 1.875 | 0476 | 63.50 | 41.28 |
| 2.000 | 0508 | 66.68 | 42.06 |
| 2.125 | 0539 | 69.85 | 42.06 |
| 2.250 | 0571 | 73.03 | 43.66 |
| 2.375 | 0603 | 76.20 | 43.66 |
| 2.500 | 0635 | 82.55 | 44.45 |
| 2.625 | 0666 | 85.73 | 45.24 |
| 2.750 | 0698 | 88.90 | 45.24 |
| 2.875 | 0730 | 93.65 | 47.63 |
| 3.000 | 0762 | 96.82 | 47.63 |
| 3.125 | 0794 | 101.60 | 47.63 |
| 3.250 | 0826 | 104.78 | 47.63 |
| 3.375 | 0857 | 107.95 | 47.63 |
| 3.500 | 0889 | 111.13 | 47.63 |
| 3.625 | 0921 | 114.30 | 47.63 |
| 3.750 | 0953 | 117.48 | 47.63 |
| 3.875 | 0984 | 120.65 | 47.63 |
| 4.000 | 1016 | 123.83 | 47.63 |
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
Laboratory Circulation Pump: A lab equipment manufacturer needed a durable seal for a 14mm shaft pump handling hot solvents. Rubber seals failed too often. Our 14mm Metal Bellow Seal provided the chemical resistance and longevity required for their warranty period.
Testimonials
Hard to find metal bellows this small with good quality. Miaoyu's 16mm seals are precise and consistent.
—Precision Equipment Manufacturer, Germany
FAQs about 12mm 14mm 16mm 18mm Metal Bellow Mechanical Seal
Q: Are these metal bellows mechanical standard sizes?
A: Yes, they conform to DIN 24960 (EN 12756) short working length standards (e.g., L1K series), making them direct replacements for many European OEM seals.
Q: What are the main advantages of using a metal bellows seal for 12mm, 14mm, 16mm, and 18mm small-shaft applications?
A: The primary advantages include a compact, all-metal welded bellows design that fits tightly in small spaces, eliminating elastomer secondary seals prone to failure. This makes the seal highly effective in handling aggressive media, high temperatures, and high rotational speeds. Its precise dimensions allow it to serve as a direct drop-in replacement, reducing installation complexity and enhancing reliability in compact pumps, mixers, and agitators.
Q: In which applications or industries are these small-sized metal bellows seals most commonly used?
A: These metal bellows mechanical seals are widely employed in industries requiring precise sealing in confined spaces, such as chemical processing, pharmaceuticals, water treatment, and small-scale industrial pumps. They are ideal for handling corrosive fluids, high-temperature environments, and equipment with limited shaft clearance, ensuring durable performance in OEM and replacement scenarios.
We supply 12mm, 14mm, 16mm, and 18mm mechanical seals with full material traceability and pressure testing. Standard lead time is 3–7 working days. Download the CAD drawing or request a quote online for immediate pricing.
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
