Split Mechanical Seal

Description;
The SPT770 Split Mechanical Seal is engineered for large or difficult‑to‑access rotating equipment where conventional seal replacement would require extensive dismantling of the driver, coupling, bearing housing, impeller, or shaft assembly. Its fully split construction allows the seal faces, secondary sealing elements, hardware, and gland components to be installed directly around the shaft, significantly reducing maintenance time and intervention scope on large pumps, turbines, agitators, and mixers. 

 

Designed for condensate, process water, river water, surface water, and general utility liquid services, the SPT770 delivers reliable sealing performance in industries such as pulp and paper, food processing, power generation, wastewater treatment, mining, and other demanding process plants where rapid seal replacement and shaft‑in‑place installation are critical. 

 

We have established a strong reputation as a leading supplier of high‑quality split mechanical seals, recognized for solutions that combine convenience with robust performance. SPT770 seals are engineered so they can be installed without disassembling the equipment: the split halves are aligned and clamped over the shaft, and the unit is then mounted similarly to a standard cartridge seal. Each seal is fully pressure‑tested at the factory prior to dispatch to help ensure leak‑tight performance and reliability in service. The design also offers a straightforward upgrade path for converting packed pumps into fully sealed systems, reducing water consumption, leakage, and maintenance associated with traditional packing. 

 

Type SPT770 features a compact, innovative design that uses a minimal number of components to simplify assembly and drastically reduce installation time. An integrated finger‑plate spring ensures consistent face loading and helps maintain uniform contact across the sealing surfaces, improving stability and wear behavior. The balanced seal face is supported by a split O‑ring acting as an effective secondary sealing element around the shaft. The seal housing is designed with standardized mounting slots, enabling compatibility across a range of equipment and pump shaft dimensions (PSDs), which enhances interchangeability and helps reduce inventory complexity. 

 

Technical Key features; 

• Semi‑cartridge design offers easy handling and installation while maintaining alignment and sealing integrity during fit‑up. 

• Finger‑plate spring design ensures consistent axial force, improving face contact, reliability, and overall sealing performance. 

• Robust gland and hardware design improves alignment stability during installation and supports accurate, repeatable positioning. 

• High mechanical strength construction using durable materials maintains performance in high‑load and heavy‑duty environments. 

• Single‑seal configuration provides a compact, efficient sealing solution suitable for a wide range of industrial water and process‑liquid duties. 

• Field‑repairable design supports in‑field inspection and replacement of components, reducing service costs and extending the seal’s service life. 

• Quick installation and easy removal eliminate the need to remove motors, couplings, or bearings, saving time, labour, and maintenance cost. 

• Designed for large‑scale equipment such as big pumps, agitators, and mixers, where ease of maintenance and shaft‑in‑place installation are critical. 

• Available with corrosion‑resistant metallurgy and elastomers selected to match process‑fluid compatibility, temperature exposure, and service severity. 

• Independent of shaft rotation direction allows reliable operation in both clockwise and counter‑clockwise rotation, simplifying selection and inventory. 

• Precision‑machined components and fine finishes ensure a correct seal fit and contact surface, supporting leak‑tight performance and long‑term reliability. 

• Stationary multiple‑spring arrangement provides uniform pressure distribution across the sealing faces and compensates for shaft misalignment or deflection. 

• Ideal for large pumps, turbines, agitators, mixers, and other difficult‑to‑strip rotating equipment where conventional seals would require extensive teardown. 

• Suitable for clean to moderately contaminated water and process liquid duties, including condensate, process water, river water, and surface water applications. 

• Balanced seal face geometry supports stable operation under moderate pressure conditions while reducing axial load on the faces, minimizing wear, and extending seal life. 

• Fully split components allow the seal faces, secondary seals, hardware, and gland to be installed around the shaft without disassembly, reducing intervention scope and unplanned downtime. 

• Fully split construction enables installation and removal without equipment dismantling, preserving alignment of motors, couplings, bearings, and shaft assemblies and significantly reducing downtime. 

 

Service Overview; 

Parameter	Value
Equipment	Large pumps, turbines, agitators, mixers and process rotating equipment
Fluid	Condensate, process water, river water, surface water and utility liquids
Service Nature	Clean to moderately contaminated liquid service; non-polymerizing fluids preferred
Operating Mode	Continuous industrial duty with rapid seal replacement and shaft-in-place maintenance

 

Specifications; 

Item	Min	Max	Typical/Notes
Size	35 mm (1.375”)	300 mm (12.000”)	Larger shaft sizes available on request
Pressure	Vacuum / 0 bar (0 psi)	10 bar (145 psi)	Typical split-seal water-service limit; verify for final duty
Temp	-40°C (-40°F)	+150°C (+302°F)	Dependent on elastomer and fluid compatibility
Speed	—	3,000 rpm	Subject to shaft size, runout and equipment condition

 

Materials; 

Component	Standard Material	Optional Material	Comment
Seal Faces	Carbon vs Silicon Carbide	Silicon Carbide vs Silicon Carbide, Tungsten Carbide	Select hard faces for abrasive or dirty water service
Elastomers	FKM / EPDM	NBR, FEP-encapsulated FKM, PTFE	EPDM preferred for many water services; FKM for oil/chemical compatibility
Metal Parts	SS 316	SS 304, Duplex SS, Alloy 20, Hastelloy	Selected according to corrosion severity and plant standards
Springs / Drive Parts	SS 316	Hastelloy, Duplex SS	For corrosive or chloride-bearing environments

 

Applications; 

• Large agitators and mixers where shaft removal is impractical. 

• Food processing wash-water, transfer and utility pumping systems. 

• Pulp and paper stock pumps, process water pumps and utility systems. 

• River water, surface water and general industrial water intake systems. 

• River water, surface water and general industrial water intake systems. 

• Mining process water pumps and large slurry-adjacent support equipment. 

• Wastewater treatment pumps, mixers, aerators and sludge-handling equipment. 

• Power generation condensate pumps, cooling water pumps and turbine auxiliaries. 

 

Operating Limits; 

Parameter	Value
Pressure	Up to 10 bar (145 psi)
Temp	-40°C to +150°C (-40°F to +302°F)
Speed	Up to 3,000 rpm
Size Range	35 mm to 300 mm (1.375” to 12.000”)

 

Engineering Note; 

Operating limits and materials are inferred from typical split mechanical seal practice for water and process utility services. Final values should be verified against SPT770 engineering drawings, seal chamber dimensions, shaft runout, fluid analysis and site operating conditions.