The Type 606 metal bellows mechanical seal is a direct interchange for John Crane® Type 606, designed for high-temperature and chemically aggressive services where conventional O-ring-mounted seals fail due to elastomer degradation. Its edge-welded metal bellows acts simultaneously as the spring element and secondary sealing member, eliminating dynamic elastomeric seals entirely.
The rotating bellows design incorporates drive lugs that transmit torque from the shaft sleeve to the rotary face, reducing torsional stress on the bellows convolutions—making it especially suitable for viscous media and frequent thermal cycling. Flexible graphite static packings provide a gas-tight seal at temperatures up to 425°C (800°F), while the all-metal construction resists coking, crystallization, and shaft fretting.
Key Features
• High-Heat Specialist: Metal bellows mechanical seal specifically designed for heat transfer oils, hot hydrocarbons, and other fluids exceeding 200°C.
• Eliminates Elastomers: Replaces temperature-sensitive O-rings with flexible graphite (Grafoil) static gaskets and a welded metal bellow core.
• Self-Cleaning: The rotation of the bellow creates a centrifugal effect that prevents coke or sludge accumulation between the convolutions
• Edge-Welded Bellows: We use precision edge-welded leaflets which offer a higher stroke-to-length ratio and better fatigue life compared to formed bellows.
• Damped Vibration: The bellow structure inherently dampens stick-slip vibration, preventing face chattering at high temperatures.
Company Advantages
30+ Years of OEM Expertise: Miaoyu Seals leverages decades of experience in manufacturing high-performance metal bellows mechanical seals, with deep technical knowledge of metallurgy and tribology for extreme conditions.
Advanced Welded Bellows Technology: As a leading metal bellows mechanical seal manufacturer, we utilize state-of-the-art edge-welding technology to produce bellows with uniform wall thickness and superior fatigue life, ensuring no leakage under thermal stress.
ISO 9001 Certified Quality Control: Our 4000+ sqm manufacturing base operates under strict quality protocols, with every metal bellows mechanical seal undergoing hydrostatic pressure testing and dimensional verification to guarantee interchangeability.
Global Supply Chain & Fast Delivery: With exports to over 50 countries, Miaoyu maintains strategic stock of critical sizes for the 606 series, offering rapid lead times to minimize customer downtime in emergency situations.
Custom Material Engineering: Beyond standard offerings, our technical team can customize the 606 seal with specific face materials (like Sintered SiC) or exotic alloys (Monel, Titanium) to meet unique process requirements.
Metal Bellows Mechanical Seal Technical Specs | Materials | ||
Pressure | ≤ 2.0MPa (Single) | Stationary Ring | Sic/TC |
≤ 6.0MPa(Double) | Rotary Ring | Carbon/Sic/TC | |
Temperature | -75°C to 400°C | Secondary Seal | Graphite |
Speed | ≤ 23 m/s | Spring and Metal Part | Stainless Steel |
Product Specifications
| Size inch | Size Code | D1 mm | D3 mm | L1 mm |
| 0.750 | 0191 | 41.28 | 58.72 | 0.875 |
| 0222 | 44.45 | 59.51 | 1.000 | 0254 |
| 47.63 | 59.51 | 1.125 | 0286 | 50.80 |
| 60.33 | 1.250 | 0317 | 53.98 | 60.33 |
| 1.375 | 0349 | 57.15 | 62.69 | 1.500 |
| 0381 | 60.33 | 63.50 | 1.625 | 0412 |
| 63.50 | 63.50 | 1.750 | 0444 | 66.68 |
| 64.29 | 1.875 | 0476 | 69.85 | 64.29 |
| 2.000 | 0508 | 73.03 | 65.07 | 2.125 |
| 0539 | 76.20 | 65.07 | 2.250 | 0571 |
| 82.55 | 69.85 | 2.375 | 0603 | 85.73 |
| 70.64 | 2.500 | 0635 | 88.90 | 70.64 |
| 2.625 | 0666 | 93.65 | 73.03 | 2.750 |
| 0698 | 96.82 | 76.20 | 2.875 | 0730 |
| 101.60 | 76.20 | 3.000 | 0762 | 104.78 |
| 76.20 | 3.125 | 0794 | 107.95 | 76.20 |
| 3.250 | 0826 | 111.13 | 76.20 | 3.375 |
| 0857 | 114.30 | 76.20 | 3.500 | 0889 |
| 117.48 | 76.20 | 3.625 | 0921 | 120.65 |
| 76.20 | 3.750 | 0953 | 123.83 | 76.20 |
Workshop
This workshop is equipped with professional processing equipment for metal bellows seals and integrated with standardized material warehousing management, enabling a one-stop production process from precision machining to finished product delivery. It ensures the machining accuracy and production efficiency of metal bellows mechanical seals, 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 metal bellows mechanical 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
Thermal Oil System: A heat transfer pump operating at 280°C was leaking due to O-ring vulcanization. We replaced it with this metal bellows mechanical seal. The static graphite seals held the temperature, and the pump has run leak-free for 3 years.
Testimonials
We upgraded all our hot oil pumps to these metal bellows seals. We haven;t changed a seal in over two years.
—Reliability Manager, Asphalt Plant
FAQs about Metal Bellows Seals for High Temperature Pumps 606
Q: Do I need cooling water for this metal bellows mechanical seal?
A: Generally, no. This seal is designed to run hot. However, we recommend a steam quench (Plan 62) on the atmospheric side to prevent oxidation (coking) of any small leakage, which could clog the seal.
Q: Is this metal bellows mechanical seal a direct drop-in replacement for John Crane Type 606?
A: Yes, the 606 model metal bellows mechanical seal is dimensionally and functionally interchangeable with the original John Crane Type 606. It is designed to fit the same gland space and shaft sizes without requiring any modifications to the pump.
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
