• Robust Drive System: Designed to handle the high torque of vertical multistage pumps without the drive lugs shearing, a common issue with brittle ceramic seals.

• Thermal Shock Resistance: TC handles rapid temperature changes (e.g., boiler feed cold starts) better than many ceramics.

• High-Strength Bellows: We use premium elastomer bellows that provide strong torque transmission to the TC face, preventing slippage.

• Solid Face Design: Unlike some competitors who use inserted faces, our TC faces are solid or securely shrink-fitted, ensuring maximum heat transfer and stability.

• Face Geometry: The faces are engineered to maintain a stable fluid film even in slurry conditions, preventing dry running during snoring (air intake) operation.

• Corrosion Resistant Binder: We use corrosion-resistant binder materials in our TC to prevent leaching in acidic mine water.

• Balanced for Pressure: The design is hydraulically balanced to operate reliably at pressures up to 25 bar, common in high-rise building booster systems.

• Positive Drive Pins: Heavy-duty drive pins ensure positive torque transmission, preventing the seal from slipping on the shaft during high-load starts.

• Isolated Spring Design: Springs are located outside the fluid in many configurations to prevent them from annealing or clogging in hot, dirty media.

• Face Material Selection: We pair these seals with Hot Water Carbon or Sintered SiC faces that maintain flatness even under thermal stress.

Shaft Size: Precision-fit for 5/8\" (15.88mm) shafts

Compliance: Engineered to NFPA 20 guidelines for jockey pumps

Construction: Simple, reliable O-Ring Face design

Material: 304/316SS, Carbon/Ceramic faces, Buna-N/EPDM O-Rings

Reliability: Long standby life, instant start capability

This face mechanical seal is engineered as a direct OEM replacement for fire-protection jockey pumps (pressure maintenance pumps) with standard 5/8″ (15.88mm) shafts. Commonly specified as a 5 8 mechanical seal in NFPA 20-compliant systems, the O-ring face design uses a carbon rotating face against a ceramic stationary seat, with 304/316SS hardware and Buna-N or EPDM secondary seals. As a purpose-built jockey pump mechanical seal, it is designed for intermittent duty cycles, resists sediment clogging in stagnant fire-water lines, and provides immediate sealing upon start-up to maintain system pressure between fire pump runs.

Value: Cost-effective, direct OEM replacement

• Shaft Protection: Unlike standard pusher seals, the sealing O-ring is static against the shaft, eliminating the need for a hardened shaft sleeve.

• Self-Aligning: The flexible rubber body allows the seal face to self-align against the stationary seat, compensating for misalignment.

• Zero-Emission Assurance: The triple arrangement allows for cascading pressure drops or high-pressure barrier fluids, ensuring absolutely no process fluid reaches the atmosphere.

• Cartridge Assembly: Despite the complexity of three seals, it installs as a single cartridge unit, simplifying maintenance on complex multi-stage pumps.

• Torque Handling: The drive band transmits torque from the spring to the face more reliably than friction-drive seals, making it suitable for higher viscosity fluids.

• Field Repairable: The simple component design allows for easy field replacement of worn faces or O-rings if the metal parts are still good.

• Positive Drive: The spring grips the shaft (interference fit) to drive the rotary head, eliminating the need for set screws that can mar the shaft.

• Balanced Face Loading: The single spring provides uniform face pressure, ensuring a tight seal even as the face wears down over time.

• Thermal Stability: SiC's high thermal conductivity helps dissipate the heat generated by two sets of seal faces, preventing barrier fluid overheating.

• Universal O-Ring Grooves: Designed with standard O-ring groove dimensions, allowing easy switching between NBR, FKM, or FFKM elastomers based on chemical needs.

The O ring balanced mechanical seal is a high-performance sealing solution engineered specifically for the demanding conditions of oil, gas, and petrochemical applications. This O ring mechanical seal is ideal for centrifugal pumps in refineries, offshore platforms, and chemical plants, providing extended service life, enhanced safety, and compliance with industry standards like API 682.

• Clog Resistant: The smooth bellow profile sheds fibers and solids, making it superior to spring pusher seals in dirty water.

• Self-Adjusting: The bellow automatically compensates for shaft end-play and runout without parts sticking or hanging up.

• Dry-Run Tolerance (with Carbon): When paired with Carbon, the Alumina face handles the intermittent dry running often found in batch mixing processes better than SiC/SiC.

• Chemical Inertness: Alumina Ceramic is inert to most acids and food products, making it ideal for food and chemical mixing tanks.

Replace Brand: John Crane mechanical seal

Specification:  type 6/type 8/type 9/type 21/109b/2100/5610/8b1/8b2

Temperature: high temperature mechanical seal

Balance: Unbalanced

Type: Multi-Spring

Accreditation: ISO, SGS, UL, ROHS

Service: OEM/ODM

Origin: China

• Positive Torque Drive: The cartridge sleeve locks firmly to the shaft, preventing the seal from slipping even when the gear pump handles cold, thick oil.

• Compact Gland: The gland plate is minimized to fit the bolt patterns of common internal gear pumps.

As a dedicated mixer mechanical seal manufacturer, MiaoYu Seals produces O-ring ceramic mechanical seals are purpose-built for top-entry and side-entry mixers, agitators and blenders in food, pharmaceutical and chemical processing. Each mixer mechanical seal features high-purity Al₂O₃ ceramic rotating faces paired with carbon graphite or SiC stationary seats, using double O-ring mounted designs to absorb shaft runout and wobble common in mixer applications. These ceramic mechanical seals are chemical-inert and dry-run tolerant, delivering leak-free performance under low-pressure slurry, viscous batch and intermittent operation—factory-direct from our ISO 9001 workshop at wholesale cost.

As a dedicated cartridge mechanical seal manufacturer, MiaoYu Seals produces alumina/ceramic cartridge mechanical seals are pre-assembled, drop-in ready solutions for sanitary pumps, homogenizers and mixers in the food, dairy, beverage and pharmaceutical industries. Featuring 99.5% high-purity Al₂O₃ ceramic rotating faces paired with carbon graphite or SiC stationary seats, these cartridge seals eliminate field assembly errors and reduce installation time. Electropolished 316L stainless steel hardware and FDA-grade EPDM or silicone O-rings resist corrosion and bacterial adhesion, while the crevice-free hygienic geometry withstands repeated CIP/SIP thermal cycling. Factory-balanced spring loading ensures consistent face contact across pressure fluctuations—all supplied direct from our ISO 9001 workshop at wholesale cost.

The 10k27 mechanical seal is a heavy-duty, welded metal bellows face seal designed specifically for top-entry reactor agitators in chemical, pharmaceutical, and petrochemical processes. It serves as a direct OEM replacement for common reactor seals, offering superior resistance to thermal cycling, high pressure, and corrosive media. With a temperature range up to 400°C (752°F) and available in Hastelloy® C276 or Inconel® 625 bellows, this metal bellows mechanical seal ensures leak-free operation even under vacuum or reverse pressure conditions. Whether you need a standard size or custom configuration, the 10k27 seal delivers reliable performance in glass-lined, stainless steel, and alloy reactors.