CM7N/CMH7N/CM74/CMH74 Mechanical Seals

Structural features:

1. Single-face design with a wave spring, offering excellent resistance to clogging. When in use, the spring direction doesn’t matter.

2. Depending on the specific application, auxiliary sealing rings can be made from nitrile rubber, fluororubber, or ethylene-propylene rubber.

3. Complies with ISO 3069, DIN 24960, and GB 6556 standards, offering excellent versatility.

4. CM7N/CMH7N feature a wave spring design, while CM74/CMH74 use a small spring design—both sizes are identical.

4. The CMH7N model features a balanced CM7N design, making it suitable for higher-pressure applications.

Applicable medium:

Oil, water, acids, bases, salts, and more

Work parameters:

Fixed substance content: ≤10%

Warm Temperature: ≤180°C

Press Force: ≤3.0 MPa

Axis Diameter: ≤200mm

Material parameters:
Main material: 304, 316L or 2205, 2507, 1.4529
Sealing ring material: Graphite, silicon carbide, tungsten carbide
Rubber materials: Nitrile rubber, fluoro rubber, ethylene-propylene rubber, silicone rubber

Main applications:

This type of mechanical seal is primarily used in various types of water pumps, chemical pumps, and sewage pumps.

Note: Since pumps have a wide range of applications, the sealing materials (friction pairs) also vary. To ensure reliable sealing performance,
The manufacturer recommends the following:
1. Clean water (without particulate matter)—Choose an alloy for the dynamic sealing pair and graphite for the static sealing pair.
2. Highly corrosive environments (conditions involving particulate matter) – For the moving seal pair, select silicon carbide; for the stationary seal pair, also choose silicon carbide.
3. Conditions involving particles and significant vibration—select (alloy) for the dynamic ring friction pair, and (alloy) for the stationary ring friction pair.
4. Customization is also available upon customer request. If no specific request is made, the default option will be (clear water).

Installation Use Requirements :

1. The radial runout of the equipment shaft should not exceed 0.04 mm, with axial runout not exceeding 0.1 mm;
2. The sealing cavity areas of the equipment should be kept clean during installation, and sealing components must be thoroughly cleaned. Ensure that the sealing end faces remain intact to prevent contaminants and dust from entering the sealing area.
3. During installation, avoid any contact or tapping to prevent damaging the mechanical seal through friction, which could lead to sealing failure.
4. During installation, apply a layer of clean machine oil to the surfaces that will come into contact with the seal, ensuring smooth installation.
5. When installing the stationary ring gland, tighten the screws evenly to ensure the stationary ring face is perpendicular to the shaft centerline.
6. After installation, gently push the moving ring by hand to ensure it moves freely along the shaft while maintaining some elasticity.
7. After installation, manually rotate the shaft—there should be no sensation of unevenness or heaviness.
8. Before starting operation, the equipment must be fully charged with the medium to prevent dry friction, which could lead to seal failure.