Product Info

This cartridge mechanical seal uses a heavy-duty single coil spring to keep stable face loading under shaft run-out and misalignment, while the cartridge construction removes on-site spring setting, shimming and face measurement during installation. It is available in carbon / silicon carbide (SiC) / sintered silicon carbide (SSiC) / tungsten carbide (TC) face combinations, with secondary seals in Viton, EPDM, Chemraz, Kalrez or Aflas.

Typical applications: water and wastewater pumps, oil and petroleum service, mild chemical duty, food-grade transfer pumps, pharmaceutical process pumps, and OEM pump rebuilds. For high-temperature or thermal-cycling duty, the same product family also covers welded metal bellows cartridge seals, which replace the dynamic O-ring with an all-metal bellows and suit hot oil, steam, vacuum and high-heat process pumps.

Key Features

• No Dynamic O-Rings: The metal bellow provides the closing force and sealing, eliminating the most common failure point (O-ring hang-up) in high-heat applications. This advanced design is distinct from a single spring mechanical seal, which relies on dynamic O-rings for secondary sealing, making this solution superior in thermal cycling conditions.

• Self-Cleaning Bellow Action: The centrifugal force of the rotating bellow throws off solids and sludge, making it essentially non-clogging, a feature crucial for maintaining the long-term reliability of a cartridge mechanical seal in abrasive or slurry services.

• High-Temperature Resilience: Capable of operating up to 400°C (depending on the secondary graphite packing) without degradation, far exceeding the operational limits of a standard single spring mechanical seal that uses elastomeric O-rings.

• Uniform Face Loading: The welded leaflet design provides even closing force across the entire face, preventing uneven wear and leakage, which is a key engineered advantage in a robust cartridge mechanical seal assembly designed for high-duty cycles.

• Hastelloy Construction: Bellows are manufactured from Hastelloy® C-276 as standard, offering superior resistance to stress corrosion cracking compared to AM350, providing a material advantage that ensures longevity in corrosive environments where a cartridge mechanical seal is deployed.

Product Specifications

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 the part machining accuracy and production efficiency of components such as the single spring mechanical seal, meeting various high-specification manufacturing requirements.

Product Research, Development and Testing

Our Product R&D and Testing focuses on optimizing cartridge mechanical 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

FAQs

Q: Which John Crane, Burgmann, Flowserve and AES seals can this single spring cartridge seal replace?

A: It is built as a pusher-type single spring cartridge seal and can cross-reference common John Crane Type 1 / Type 21 style units, Burgmann BT-P / MG series cartridges, Flowserve / Durametallic pusher cartridges, and AES M07 / M010 class seals. Final interchange depends on shaft diameter, stuffing box depth and gland bolt circle—send the old seal drawing for exact confirmation.

Q: Why use a single spring cartridge seal instead of a multi-spring seal?

A: A single heavy-duty coil spring is less sensitive to sludge, fibrous stock and dirty water, and is easier to clean in wastewater or pulp service. Multi-spring seals give smoother face loading at high speed, but small springs clog faster. For 10–100 mm shafts, dirty liquids and OEM pump rebuilds, the single spring cartridge design is usually the more reliable choice.

Q: Can you supply OEM/ODM single spring cartridge seals with custom materials?

A: Yes. MIAOYU supplies both OEM replacement and ODM custom units: carbon / SiC / SSiC / TC faces, Viton / EPDM / Kalrez / Chemraz secondary seals, and 316SS or Hastelloy C springs and metal parts. We manufacture to customer pump models, sample seals or dimensional drawings, with ISO/SGS-level inspection and export packaging.