MAINTENANCE LO1.2

useful guide in selecting the correct type of gasket, sealant, and packing.

International Marine Purchasing Association (IMPA) Catalogue

They are formulated to withstand saltwater, sunlight, and temperature fluctuations, bonding materials like wood, metal, fiberglass, and plastics

Sealants

Sealants are essential for ships to

• Prevent water ingress

• Maintain structural integrity

• Resist harsh marine environments

Types of Sealants

• Butyl Rubber Sealants –

• Polysulfide Sealants –

• Polyurethane Sealants –

• Silicone Sealants –

Bedding deck hardware, sealing joints

Butyl Rubber Sealants

Flexible, resistant to saltwater

Polysulfide Sealants

Versatile sealing for boats and ships

Polyurethane Sealants

Above-waterline sealing applications

Silicone Sealants

mechanical seal, usually a thin piece of flexible material, used to fill the space between two mating surfaces to prevent leakage. Common materials: rubber, cork, paper, metal.

gasket

Types of Gaskets

• Flat Gaskets – Low-pressure applications

• Spiral Wound Gaskets – High-pressure/high-temperature pipelines, boilers

• Ring Joint Gaskets – High-pressure oil/gas pipelines

• Rubber Gaskets – Automotive, aerospace, HVAC

• Metal Gaskets – Extreme temperature/pressure, chemical plants

• Elastomeric Gaskets – Rubber + metal layers for resilience

• Camprofile Gaskets – Serrated metal core with bonded non-metallic material

• Cork Gaskets – Automotive engines, fuel pumps

• Graphite Gaskets – High resistance to heat, chemicals, pressure

• PTFE (Teflon) Gaskets – Chemical resistance, non-stick, food/pharma industries

TG Low-pressure applications

Flat Gaskets

Tg Spiral Wound Gaskets

High-pressure/high-temperature pipelines, boilers

Tg High-pressure oil/gas pipelines

Ring Joint Gaskets

Tg Automotive, aerospace, HVAC

Rubber Gaskets

Tg Extreme temperature/pressure, chemical plants

Metal Gaskets

Rubber + metal layers for resilience

Elastomeric Gaskets

Tg Serrated metal core with bonded non-metallic material

Camprofile Gaskets

Tg Automotive engines, fuel pumps

Cork Gaskets

Tg High resistance to heat, chemicals, pressure

Graphite Gaskets

Tg Chemical resistance, non-stick, food/pharma industries

PTFE (Teflon) Gaskets

sealing materials, typically braided or formed rings, used to prevent leaks around rotating shafts in pumps and machinery.

Packings

Functions of Packings

• Sealing – Prevent leakage of fluids/gases

• Lubrication – Small leakage lubricates packing and shaft

• Heat Removal – Leakage dissipates friction heat

Types of Packings

• O-Rings – Can function as both gaskets and packings

• Gland Packings – Compressed within stuffing boxes

• Mechanical Seals – Prevent leakage between rotating shafts and stationary parts

• Oil Seals – Keep pump seals lubricated, prevent leakage

• Labyrinth Seals – Non-contact seals using interlocking grooves (e.g., stern tube, turbocharger)

Can function as both gaskets and packings

O-Rings

Compressed within stuffing boxes

Gland Packings

Prevent leakage between rotating shafts and stationary parts

Mechanical Seals

Keep pump seals lubricated, prevent leakage

Oil Seals

Non-contact seals using interlocking grooves (e.g., stern tube, turbocharger)

Labyrinth Seals

Difference Between Gaskets and Packings

• Gaskets – Seal between stationary surfaces, rely on compression

• Packings – Used where there is relative motion, often in rotating machinery

Types of Adhesives

• Epoxy Adhesives – Strong bonding, boat building and repairs

• Polyurethane Adhesives – Versatile, marine bonding

• Methacrylate Adhesives – Fast-curing, underwater applications

• Silicone Adhesives – Excellent water resistance and sealing

• Contact Cement – Rubber-based, quick permanent bonds

Strong bonding, boat building and repairs

Epoxy Adhesives

Versatile, marine bonding

Polyurethane Adhesives

Fast-curing, underwater applications

Methacrylate Adhesives

Excellent water resistance and sealing

Silicone Adhesives

Rubber-based, quick permanent bonds

Contact Cement