
Astra Seals AS M74-D Double End Mechanical Seal for Chemical Centrifugal Pumps, KSB/Kaiquan Water Pumps and Double Suction Pumps. Double end, small spring, unbalanced, independent direction of rotation, drive sleeve transmission, back to back design. Alternative to KSB and Kaiquan original seal components. Inner diameter: 20 mm to 300 mm. Pressure: ≤1.6 MPa, Temperature: -20~180°C, Linear Speed: ≤20 m/s. Standards: DIN24960, ISO3069, GB6556.
Rotary Face / Stationary Face / Elastomer / Spring / Metal Parts
Carbon/SiC/TC (Rotary) / Carbon/SiC/TC (Stationary) / NBR/EPDM/Viton/FFKM (Elastomers) / SS304/SS316/PH17-4/HC-276 (Springs) / 410S/SS304/SS316/SS316L/Hastelloy (Metal Parts)
| Model | Materials | GA |
|---|---|---|
| M74-D | Carbon/SiC/TC (Rotary) / Carbon/SiC/TC (Stationary) / NBR/EPDM/Viton/FFKM (Elastomers) / SS304/SS316/PH17-4/HC-276 (Springs) / 410S/SS304/SS316/SS316L/Hastelloy (Metal Parts) | — |
| AS M74D & M74R-D | SiC/TC (Rotary) / Carbon/SiC (Stationary) / Viton/EPDM/PTFE (Elastomers) / SS316/HC276 (Springs) / SS304/SS316L (Metal Parts) | — |
Pressure
1.6 MPa or less
Temperature
-20 ~ 180 ºC
Linear Speed
20 m/s or less
Mediums
Oil, water, acid, alkali, organic solvents and mediums that are easy to be crystallized or have granules and high viscosity.
Customization Available
Changes of materials for getting other operating parameters are possible. Contact us with your requirements.

Astra Seals AS H75 Series Cartridge Mechanical Seal for Boiler Feed Pumps. Single end, multiple springs, balanced, independent rotary direction, coil driven. Simple and reliable transmission, easy to install with stable sealing performance and long life. Inner diameter: 50 mm to 200 mm. Pressure: ≤5 MPa, Temperature: ≤200°C, Linear Speed: ≤30 m/s. Standard: APIWidely used in boiler feed pumps for power plants, booster pumps and other medium pressure high speed applications.

Astra Seals AS H76 Single Spring Mechanical Seal for Mixers and Boiler Feed Pumps. Single end, single spring, balanced, independent rotary direction, coil driven. Simple and reliable transmission, easy to install with stable sealing performance and long life. Inner diameter: 50 mm to 200 mm. Pressure: ≤5 MPa, Temperature: ≤200°C, Linear Speed: ≤30 m/s. Standard: APIWidely used in boiler feed pumps for power plants, booster pumps and other medium pressure high speed applications.

Astra Seals AS 8B1D Mechanical Seal for Boiler Feed Pumps and Power Plants. Single end, multiple springs, balanced, independent rotary direction, coil driven. Simple and reliable transmission, easy to install with stable sealing performance and long life. Inner diameter: 50 mm to 200 mm. Pressure: ≤5 MPa, Temperature: ≤220°C, Linear Speed: ≤30 m/s. Standard: APIWidely used in boiler feed pumps for power plants, booster pumps and other medium pressure high speed applications.
Compare adjacent seal types to find the best fit for your service conditions, pressure and temperature range.

Universal and OEM cartridge seals for pumps, compressors, and general rotating equipment.

Metal and PTFE bellow seals for high-temperature, high-pressure, and corrosive applications.

Elastomer bellow mechanical seals (rubber bellows) for HVAC, wastewater, clean-water, and light chemical pumps — direct John Crane Type 21 / Type 6A, Sepco 500 and EagleBurgmann MG1 replacements to ISO 3069 / DIN 24960.

Seal support systems including API Plan 52/53 vessels, cyclone separators, flow units, and barrier liquid boosters.