How To Choose Engineering Mechanical Seals?

IFour Key Factors for Sealing Component Selection

1.Working environment

Temperature range (-30℃ to 200℃)

Pressure rating (low pressure/High pressure/Ultra-high pressure)

Medium type (hydraulic oil, water, corrosive liquid, etc.)

2.Exercise mode

Static sealing (end face sealing)

Dynamic sealing (rotating shaft, reciprocating motion)

3.Equipment compatibilityCompatible brand models (such as CAT excavators, Komatsu pumps and valves)

Dimensional accuracy (ISO/DIN standard or non-standard customization)

4.Lifespan and Cost

Requirements for wear resistance

Maintenance frequency and replacement cost

IIComparison of Key Materials for Mechanical Seals

1.Nitrile rubber (NBR)

Features: Oil-resistant, high cost performance, suitable for general industrial applications.

Application: Hydraulic systems, pumps, low-pressure environments.

2.Fluorocarbon rubber (FKM)

Features: High-temperature resistance, chemical corrosion resistance, and excellent sealing performance.

Application: Chemical processing, high-temperature oil, corrosive media.

3.Ethylene propylene diene monomer (EPDM)

Features: Resistant to water, steam and polar solvents; Poor oil resistance.

Application fields: water pumps, food processing, pharmaceuticals and other industries.

4.Polytetrafluoroethylene (PTFE)

Features: Excellent chemical inertness, low friction, and high temperature resistance.

Application scope: Corrosive fluids, ultra-clean environments (such as semiconductors).

5.Silicone rubber (VMQ)

Characteristics: It is flexible at low temperatures, has good biocompatibility, but weak mechanical strength.

Application: Medical devices, food-grade equipment, low-stress sealing.

IIICommon Faults and Maintenance Guide

1.Analysis of the cause of the leakage

Installation error: The sealing lip was installed in the wrong direction and scratched.

Aging and cracking: The material is not resistant to high temperatures or medium corrosion.

Size mismatch: Too tight or too loose fit with the shaft/slot.

2. Replacement steps

Disassembly inspection: Clean the sealing groove and check for wear marks.

Dimension verification: Measure the inner diameter, outer diameter and wire diameter of the old seal.

Correct installation

Use special tools (such as guide sleeves) to avoid cutting.

Apply grease (silicone grease or hydraulic oil).

3. Techniques for prolonging life

Regularly check whether the sealing lip is dry-ground.

Avoid mixing hydraulic oils of different brands.

The correct selection of seals can reduce the risk of equipment downtime. If you need customized sealing solutions or material test reports, please feel free to contact our technical team!