Mechanical seal john crane
Type SB2
Low-emission, High-pressure Heavy-duty Dual-cartridge Seals – Type SB2
The Safeseal Type SB2 is a dual-cartridge seal. Its double-balanced design ensures the reliability and longevity of the seal in the most demanding conditions. The Type SB2 seal is ideal for use with environmentally hazardous and abrasive fluids, most often used in pumps in pulp mills, minerals processing and other slurry duties up to 40 percent solids by weight and a solids hardness of 8 Mohs. The Type SB2 seal is widely used with other process equipment including agitators.
Several variant of the design available for different services:
Type SB2A — designed for ANSI standard dimensions
Type SB2A-PR — designed for ANSI standard dimensions, including integrated pumping device
Type SB2B — designed for big bore dimensions
Type SB2B-PR — designed for big bore back plate dimensions
Type SB2S — designed for special dimensions, including metric sizes
Type SB2S-PR — designed for special dimensions, including integrated pumping device
Product Description Type SB2
At John Crane, we partner with you to find solutions that will best ensure optimal function of your machinery in any application. Our range of heavy duty cartridge seals are versatile and easy to install, suit a wide range of duties and are commonly used in applications in paper and board mills, power plants and other process equipment. The SB1A and SB2A ranges are suited for ANSI specific pumps.
Advanced technical features, such as patented seal face holders and elastic thrust rings, decrease the risk of seal damage and extend seal life. The balanced design of the SB1 ensures that pressure shocks do not affect seal operation, providing ultimate reliability. The SB1A is suitable for a wide range of demanding applications including water, oils, solvents and pulp with consistency of up to 2 percent. The SB2 and SB2A provide the longevity and reliability needed for the most demanding and abrasive applications, reducing risk of damage to your equipment and operators
Table Parameters Type SB2
| Temperature Limits | 350°F/180°C
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|---|---|
| Pressure Limits | Process pressure: 290 psi(g)/20 bar(g)
Barrier fluid: 215 psi(g)/15 bar(g)
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| Speed Limits | 65fps/20m/s
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| Standard Materials | Seal faces: SiC/Carbon or SiC/SiC
O-rings: PTFE, EPDM, Viton, FFKM
Metals: AISI 329 and 316 standard, titanium, Hastelloy, UHB, 904, SAF 2507 for sea water applications
Springs: Nimonic steel
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Features Type SB2
- California Residents: PROPOSITION 65 WARNING
- Seal faces are installed using a patented heat shrink process ensuring correct, distortion-free face alignment at all recommended temperatures.
- The springs are located in the stationary body of the seal in the seal water (barrier fluid). The seal water washes the springs, preventing process chemical corrosion and reduces the risk of the springs becoming clogged. Shaft misalignment does not vibrate or wear out the O-rings.
- PTFE slot rings replace the traditional O-rings in places where they are exposed to the product, preventing sticking.
- Protected faces, the seal face carriers are driven by machined fits, preventing metal stress from distorting the face.
- Patented double-balanced design allows the use of both pressurized and unpressurized seal water (barrier/buffer fluid) and prevents face overload.
- SB2 series seals will accept ± 0.080″/± 2.0mm axial movement (shaft end play) during normal operation due to their piston design.
- Impeller adjustments do not affect face stress or spring strength.
Recommended Applications Type SB2
- Process pumps
- Other rotating equipment