Type CK 725 (D)

Manufacturer: John Crane

Mixer and Agitator Cartridge Seal to Vessel Seal Standard DIN 28138 for Steel Chemical Reaction Vessels - No Bearing Integrated
The Type CK 725 is a dual pressurized, liquid lubricated cartridge seal for top entry mixing and agitating equipment. A value engineered design, high level of standardization and broad material options make this seal a cost efficient solution for general duty applications in the chemical and pharmaceutical industry. Standard versions are compliant with vessel seal standard DIN 28138 Parts 1 and 3. They are designed for use on steel made agitated chemical reaction vessels to DIN 28136, to fit on a mounting flange to DIN 28141 and agitator shaft end dimensions to DIN 28154. Hardware adaptations to fit to non DIN equipment are available on request.

By exchanging the seal faces, a Type CK 725 wet seal can easily be converted to a contacting, dry running seal. Type name then changes to Type CK 725D. Advantages of contacting dry running seals include freedom from contamination by barrier liquid and a low face wear rate, together with a cost efficient, easy to install (gas) supply system. To simplify inventory, seal components are standardized with the other seal types of this family CK 726(D) and CK 736(D).

The seal is suitable for operation in potentially explosive atmospheres. Depending on individual explosion protection requirements, the seal operating limits may differ from the values given in the parameters section. Furthermore, additional monitoring devices may be required.

For undemanding applications, the wet seal versions can be operated without pressurizing the barrier liquid. Please consult John Crane.

• Dual cartridge seal without bearing to DIN 28138 for stainless steel vessels.
• Fits mounting flange to DIN 28141 and shaft ending to DIN28154.
• Back to back seal arrangement with unbalanced faces.
• Reversed pressure capabilities inboard.
• Liquid lubricated (CK 725) or dry running (CK 725D) face versions available.
• Non standard sizes, special designs and material options are available on request.
• Debris well and cooling flange options available.
• Suitable for application in explosive areas. Certificates of conformity according to European Directive 94/9/EC (ATEX) Cat. 1, 2, or 3 on request.
• Limits of operation without pressurized barrier fluid are available upon request.

TEMPERATURE LIMITS40°F to 392°F/ 40°C to 200°C

PRESSURE LIMITSVacuum to 16 bar(g) Dry running variant up to 6 bar(g)

SPEED LIMITS400fpm/2m/s

SIZE LIMITSDry running variant: 300fpm/1.5m/s 40mm to 160mm