In this guide, we introduce the most common John Crane interchangeable models and list the Top 10 John Crane mechanical seal replacement manufacturers in China, including NINGBO MIAOYU MACHINERY TECHNOLOGY CO., LTD (MIAOYU).
Before reviewing the manufacturers, it is important to understand the mainstream John Crane mechanical seal types that Chinese suppliers typically replicate:
1. John Crane Type 1 & Type 2 (Elastomer Bellows Seals)
Style: Unbalanced, rubber bellows, externally mounted or internally mounted.
Features: Simple structure, independent of rotation direction, shaft-protecting bellows, cost-effective.
Applications: Water pumps, HVAC, light chemical duty, general service liquids.
2. John Crane Type 21 & Type 502
Style: Unbalanced O-ring pusher seals with single coil spring.
Features: Type 502 is the heavy-duty version of Type 21; both comply with ISO 3069 / EN 12756; easy to install.
Applications: Clean water, mild chemicals, boiler feed pumps, circulation pumps.
Style: Elastomer bellows component seal.
Features: Short installed length (L1 standard), excellent for space-limited pumps, short spring avoids clogging.
Applications: Wastewater, submersible pumps, standard industrial pumps.
4. John Crane Type 680 / 682 (Cartridge Seals – API 682 Category 1)
Style: Balanced or unbalanced cartridge seal, O-ring pusher.
Features: Pre-set assembly reduces installation error, meets API 682 standards, optional quench or flush plans.
Applications: Refinery charge pumps, petrochemical process pumps, high-pressure hydrocarbon service.
Style: Welded metal bellows, balanced cartridge design.
Features: Handles high temperatures (up to 400°C+ with proper flush), no elastomers in hot zones, excellent for thermal shock.
Applications: Hot oil systems, steam turbines, high-temp chemical reactors, refinery services.
The following Chinese companies are well-recognized for producing dimensionally interchangeable Burgmann mechanical seal and John Crane mechanical seal equivalents. They serve global MRO markets with ISO-certified quality and competitive pricing.
1
NINGBO MIAOYU MACHINERY TECHNOLOGY CO., LTD (MIAOYU)
Ningbo, Zhejiang
Specializes in OEM/ODM replacements for John Crane mechanical seal series (Type 1, 2, 21, 502, 2100, 680, 4610, 5610) as well as Burgmann mechanical seal models (MG1, MG12, M3N, M7N, H75N, etc.).
Strengths: 100% dimensional interchangeability, premium SiC/TC/Carbon face options, fast lead time, global export experience (USA, Europe, India), technical support for custom configurations.
Best For: Buyers seeking a reliable one-stop source for multi-brand interchangeable seals with strong engineering backup.
2
Sinoseal Holding Co., Ltd. (中密控股)
Publicly listed company
A publicly listed Chinese seal manufacturer with strong R&D. Produces API 682 cartridge seals and John Crane-type equivalents for refinery and power plant applications.
Best For: Large-scale projects requiring API-compliant engineered seals.
3
Ningbo Victor Seals Co., Ltd.
Established 1984
Established in 1984, Victor Seals offers a full range of John Crane replacement elastomer bellows and cartridge seals. Their products are registered in 30+ countries.
Best For: Distributors wanting an established international brand name.
4
YALAN Seals (Yalan Pump Seals)
Multiple patents holder
Holds multiple patents and produces 3,600+ seal designs. Provides John Crane and Burgmann-compatible replacements with broad design coverage. ISO 9001 certified.
Best For: Buyers needing specialized chemical or high-temp pump seals.
5
Lepu Seal (Guangzhou Lepu Machinery Seal Co., Ltd.)
20+ years experience
Over 20 years of experience in aftermarket replacements. Covers John Crane Type 1/2/21/502/2100 and cartridge seals. Known for stable quality and reasonable pricing.
Best For: Cost-conscious MRO buyers needing standard catalog seals.
6
Ningbo Zhongli John Seals Co., Ltd. (ZL Seals)
Founded 2000
Founded in 2000, specializes in rubber bellows, O-ring pusher, and cartridge seals interchangeable with John Crane, Burgmann, Grundfos, and Flygt.
Best For: Mixed orders combining pump seals and spare parts.
7
Trisun Parts Manufacture Co., Ltd.
Shanghai / Jiangsu
ISO-certified manufacturer producing Type 1, Type 21, Type 502, and metal bellows equivalents. Exports heavily to the USA and Australia.
Best For: North American market distributors.
8
Guangzhou Bogeman Mechanical Seal Co., Ltd.
Specialized manufacturer
Focuses on John Crane-type cartridge seals (680/682 series) and elastomer bellows seals. Provides custom-engineered solutions.
Best For: Petrochemical and water treatment sector buyers.
9
Hefei Supseals International Trade Co., Ltd.
Material traceability focus
Supplies John Crane and Burgmann replacement seals with emphasis on material traceability and dimensional accuracy. Active in Middle East and Asian markets.
Best For: Buyers requiring detailed material certification.
10
Zhejiang Uttox Fluid Equipment Co., Ltd.
Since 1990
Long-standing manufacturer (since 1990) with a focus on Flygt-compatible submersible seals and John Crane general-purpose equivalents. Exports to 50+ countries.
Best For: Wastewater and submersible pump seal replacements.
Why Choose a Chinese John Crane Mechanical Seal Replacement?
A high-quality John Crane mechanical seal replacement from reputable Chinese manufacturers like MIAOYU delivers:
Drop-in Fit: Manufactured to original John Crane dimensional standards (D, d1, L).
Material Flexibility: Carbon / SiC / TC / SSiC faces with NBR, EPDM, FKM, or FFKM secondary seals.
Cost Savings: Typically 40–70% lower cost than OEM without sacrificing performance.
Reduced Downtime: Stock availability and shorter supply chains vs. imported OEM.
Q: Are Chinese replacements 100% compatible with original John Crane seals?
A: Reputable manufacturers such as MIAOYU produce seals to the exact same dimensional drawings as the original John Crane mechanical seal, ensuring direct drop-in installation.
Q: Which model is most commonly replaced?
A: Type 1, Type 21/502, and Type 2100 elastomer bellows seals are the highest-volume replacements, followed by cartridge Type 680/682 for process pumps.
Q: Can I get custom materials or non-standard sizes?
A: Yes. Most top-tier Chinese suppliers, including MIAOYU, offer ODM customization for face combinations, seat types (G6/G60/G9), and shaft sizes.
