WEL-COME

A Seminar on

“Mechanical Seal”

By Mr.Kusekar S.K.

Under The guidance

of Dr.Pawar M.S.(Principal)

BMIT,Solapur

Contents 1. Introduction 2. Types of Mechanical Seal 3. Mechanical Seal Failure modes and cause Events 4. Design Component 5. Material used for Mechanical Seal 6. Mechanical Seal Design with superior Thermal Char. 7. Mechanical Seal Application 8. Conclusion 9. References

Introduction

Mechanical Shaft Seal

Types of Mechanical Seal

• Seal Head Type

• Seal Seat Type The best way to identify the seal seat type is by visually matching the sample to drawing or pictures.

DMR JOHN CRANE SEALOL PAC-SEAL

Type A Type6 TypeA Type 16

TypeB Type6A TypeB Type68

TypeC Type21 Type43 Type2

TypeD - - -

TypeE Type 1 Type 43 Type51

Mechanical Seal Failure Modes and Cause Events

• A mechanical seal may fail during its service by wear, corrosion, fracture, and so on.

• In a plant, leakage from a machine or machine components is reported as a failure mode or symptom.

• A cause event that singly or in combination with other cause events leads to various failure modes or a general failure mode, includes, design-related, process-related, and operation- and maintenance-related cause events.

• The list of cause events is prepared after consultation with design and practicing engineers.

• Some of these cause events will directly influence the failure mode of a mechanical seal, whereas, the others will be influenced by a stage relation

Cause Event 1. Direct Cause Event1. A problem of abrasive contaminants,2. Improper seal material, 3.Problem of maintaining pressure velocity coefficient (PV value),4. Excessive fluid pressure,5. Improper seal design, 6.Insufficient seal lubrication, excessive seal face temperature,7. Failure of secondary seal,lead to seal failure directly. For example, excessive seal face temperature leads to high heat generation causing seal failure. Similarly insufficient seal lubrication leads to seal failure because inadequate lubrication causes high heat generation in the seal, which leads to seal failure. These cause events are called direct cause

2. Indirect Cause Event

1.problem of misalignment, 2.improper seal assembly,3. installation and4. poor maintenance practices are called indirect cause events. For example, poor maintenance practices such as inadequate cooling lead to an increase in the seal face temperature, which further causes seal failure.. 

Design Component

By way of example, a simple mechanical seal design has 7 components 1. Stationary component; commonly referred to as the seat .2. Stationary component sealing member.3. Rotating component.4. Rotating component sealing member.5. Spring.6. Gland plate.7. Clamp ring.

Design Component

Material used for Mechanical Seal

1.Carbon 2.Resin impregnated carbon3.Antimony impregnated carbon 4.Dry running carbons5.Acid grades6.Silicon carbides7.Self sintered silicon carbide8.Reaction bonded silicon carbides9.Ceramic materials

MECHANICAL SEAL DESIGN WITH SUPERIOR THERMAL CHARACTERISTIC

• Heat Transfer Consideration in Mechanical Seals• H= P VA f

Thermal Effects on Seal Performance and Behavior

• Thermally Induced Radial Taper• Thermally Induced Waviness• Heat Checking and Hot Spotting• Blistering of Carbon

# Effects on Process Fluid Heat Exchangers, Surface Treatments and Coatings

Mechanical Seal Application

• Mechanical seals are used to prevent leakages in pump

• Compressor• Mechanical shaft seal.• Any failure of mechanical seal hazardus to the

system.

Conclusion• A mechanical face seal is an important component of variety

of pumps used in chemical,petrochemical and process industry. The primary function of a mechanical seal is to prevent leakage of the process fluid from the pump housing and shaft to the environment.The factors that affect the performance of a mechanical seal to leak are friction, wear and its thermal characteristics. Improving upon the thermal characteristics of a mating ring in a mechanical seal would enhance its performance. Implanting a heat exchanger in the mating ring hold great promise for improving the performance of mechanical seals from the viewpoint of reducing heat at the interface and hence enhance the performance of the mechanical seal.

Mechanical seals are used to prevent leakages in

pump,compressor,mechanical shaft seal.Any failureofmechanical seal

hazardous to the system

References• R. H. Warring, Seals and Sealing Handbook, 1 st Edition, Trade and Technical

Press Ltd.; 1981.       

• G. Lendaris, "Structural modeling - A tutorial guide", IEEE Trans Syst, Man Cybernatics, Vol. 12, pp. 807-840, 1980.       

• F. Harry, "Graph Theory", Narosa Publishing House: New Delhi, India; 1988.       

• F. Harary, R. Z. Norman, and O. Cartwright, "Structural Models - An Introduction to the Theory of Digraphs", John Wiley and Sons Inc.: NY, USA; 1965.       

• R. Sehgal, O. P. Gandhi, and S. Angra, "Failure cause analysis of welded joints", IJEMS, Vol. 14, pp. 24-30, 2007.       

           

Web References

• 1.www.google.com 22/10/2012

• 2.www.sciencedirect.com 25/10/2012

• 3.www.pdf search engine.com 27 /10/2012• 4.www.fadoo engineers.com

30/10/2012

Thank You For Your Kind Attention……