Mechanical Seals

This library consists of 4 interactive, on-line lessons. These lessons were designed for persons with a basic understanding of the operation and maintenance of pumps, agitators, and rotating equipment.

Introduction to Mechanical Seals


Description: This is the first lesson in the iKNOW™ Mechanical Seals Library. The lesson explains the purpose and basic components of mechanical seals. The participant is instructed in the identification and characteristics of materials commonly used to make seal faces and seal hardware, and to understand the limitations of seals. Characteristics, limitations, and application of packing are also discussed.

Prerequisites: None

Topics:

Purpose of Mechanical Seals

Primary Seals

Secondary Seals and Seal Hardware

Characteristics and Limits of Mechanical Seals

Packing

Objectives:

  • Explain the purpose of mechanical seals
  • Identify the basic components of a mechanical seal
  • Identify the types of materials commonly used to make seal faces and elastomers
  • Describe the characteristics of materials commonly used to make seal faces
  • Identify the types of materials commonly used to make seal hardware
  • Describe the characteristics of materials commonly used to make seal hardware
  • Identify the primary sealing points of a mechanical seal
  • Identify the secondary sealing points of a mechanical seal
  • Identify the characteristics and limitations of mechanical seals
  • Describe the characteristics of packing
  • Identify applications in which packing is installed to control process leakage
  • Explain when packing should be replaced by a mechanical seal

Mechanical Seal Designs


Description: This is the second lesson in the iKNOW™ Mechanical Seals Library. It describes various seal designs and their application. The lesson also describes conditions that may affect mechanical seal performance.

Prerequisites: Knowledge of mechanical seal components is recommended.

Topics:

Seal Designs

Single Seals

Double Seals

Cartridge Seals

Fluid, Temperature, and Operating Considerations

Objectives:

  • Describe a single seal and list its uses
  • Describe a double seal and list its uses
  • Describe a tandem seal and list its uses
  • Describe a cartridge seal and list its uses
  • Define an inside seal and explain its use
  • Define an outside seal and explain its use
  • Explain how process fluid affects mechanical seals
  • Explain how temperature affects mechanical seals
  • Explain how operational conditions affect mechanical seals

Failure Analysis


Description: This is the third lesson in the iKNOW™ Mechanical Seals Library. This lesson demonstrates the steps necessary to prepare to remove, and to remove, a failed mechanical seal. The lesson trains the participant in failure analysis to determine the cause of seal failure and identify the means to correct the problem or condition that caused the failure.

Prerequisites: Knowledge of mechanical seal components and design.

Topics:

Removing the Seal

Causes of Seal Failure

Chemical Attack

Damage from Heat and Mechanical Action

Failure Analysis

Objectives:

  • List the steps necessary to prepare for removing a failed mechanical seal
  • List the steps to removing a failed mechanical seal
  • Perform a failure analysis to determine the cause of seal failure
  • Identify the means to correct the problem or condition that caused seal failure
  • List the steps to follow to properly analyze seal failure
  • Describe seal damage caused by chemical attack
  • Describe seal damage caused by heat
  • Describe seal damage caused by mechanical action

Mechanical Seal Maintenance


Description: This, the final lesson in the iKNOW™ Mechanical Seals Library, trains the learner in seal disassembly and reassembly, 0-ring installation, and seal installation.

Prerequisites: Knowledge of mechanical seal components and design, and review of the lesson Failure Analysis is recommended.

Topics:

Seal Disassembly

O-Ring Installation

Seal Reassembly

Seal Installation

Objectives:

  • Remove a failed mechanical seal
  • Disassemble a failed mechanical seal
  • Identify the correct tool for O-ring extraction
  • Remove O-rings from a mechanical seal
  • Replace O-rings on a mechanical seal
  • Perform the preliminary checks prior to seal installation
  • Reassemble and install a new or repaired mechanical seal