Coheretech

Elastomeric Seals: Types, Materials, Applications, Standards, and Troubleshooting

Elastomeric seals are flexible components used to prevent fluid or gas leakage between mating surfaces. They are widely used in industries such as automotive, aerospace, oil & gas, and manufacturing due to their resilience, chemical resistance, and ability to withstand extreme temperatures and pressures.

Type Description Applications
O-Rings Circular cross-section, sit in grooves Hydraulic systems, pumps, valves
Gaskets Flat seals between flanges Pipe joints, engines, compressors
D-Rings D-shaped cross-section Low-pressure static sealing
Square Rings Rectangular cross-section High-pressure hydraulic systems
Type Description Applications
Rotary Shaft Seals Prevent leakage along rotating shafts Pumps, motors, gearboxes
Reciprocating Seals For linear motion systems Hydraulic cylinders, pistons
Lip Seals Flexible lip contacts moving part Automotive wheel bearings, transmissions
U-Cups U-shaped for pistons & rods Hydraulic and pneumatic cylinders

Material Configurations & Properties

Component Common Materials Key Properties Applications
Primary Sealing Faces Silicon Carbide (SiC), Tungsten Carbide (WC), Carbon Graphite High wear resistance, thermal stability High-speed pumps, abrasive fluids
Secondary Seals (O-rings, gaskets) Nitrile (NBR), FKM (Viton®), PTFE (Teflon®) Chemical resistance, flexibility Chemical processing, food-grade seals
Metal Parts (Springs, Housings) Stainless Steel (SS 316), Hastelloy, Titanium Corrosion resistance, strength Offshore, marine, acidic environments
Bellows PTFE, FKM, Metal (Inconel) Flexibility, thermal cycling resistance High-temp/pressure systems

Technical Standards & Specifications

Material Temperature Range Chemical Resistance Key Features Common Applications
Nitrile (NBR) -40°C to +120°C Good for oils, fuels Cost-effective, durable Automotive fuel systems, hydraulic seals
Fluoroelastomer (FKM/Viton®) -20°C to +200°C Excellent for fuels, acids High heat resistance Aerospace, chemical processing
Silicone (VMQ) -60°C to +230°C Moderate chemical resistance Flexible, biocompatible Medical, food-grade applications
Ethylene Propylene (EPDM) -50°C to +150°C Resistant to water, steam Weather-resistant Outdoor seals, HVAC systems
Polyurethane (AU/EU) -40°C to +80°C Good abrasion resistance High wear resistance Hydraulic seals, industrial machinery
PTFE (Teflon®) -200°C to +260°C Exceptional chemical resistance Low friction, non-stick Chemical processing, high-purity seals

Standard Sizes & Dimensions (O-Rings as Example)

AS568 Size Inner Diameter (mm) Cross-Section (mm) Common Applications
001 1.78 1.78 Small pneumatic systems
010 6.07 1.78 Hydraulic fittings
112 19.63 2.62 Automotive fuel systems
320 74.63 3.53 Industrial pumps
430 139.73 5.33 Large hydraulic cylinders

Troubleshooting Common Seal Failures

Issue Possible Cause Solution
Extrusion High pressure, incorrect hardness Use harder material (e.g., 90 Shore A)
Swelling Chemical incompatibility Switch to FKM or PTFE
Cracking Ozone/UV exposure Use EPDM or ozone-resistant material
Abrasion Rough surfaces, misalignment Polish mating surfaces, use polyurethane
Compression Set Over-compression, high temperature Use high-temperature material (FKM)

How to Order Mechanical Seals

Safety & Handling Guidelines

  • Storage:  Keep in cool, dark place away from UV/ozone exposure.
  • Installation:  Avoid twisting or overstretching seals.
  • Lubrication :Use compatible lubricants (silicone grease for NBR).
  • Chemical Exposure :Verify material compatibility before use.
  • Disposal: Follow environmental regulations (some elastomers are not biodegradable).