How to find the right Seals & O-Rings AI guide
Written by an AI model from its trained knowledge.
What the AI looks for in Seals & O-Rings
- Elastomer compatibility with the fluid
- Match compound to media: NBR for petroleum oils and fuels, FKM for high heat and aggressive chemicals, EPDM for water, steam and glycol brake fluid, silicone for static food or wide-temperature use The wrong compound swells, hardens or dissolves, and most seal failures come from this mismatch rather than from size.
- Standard size system
- Identify AS568 dash size (inch) or ISO 3601 / metric ID x cross-section before buying; measure cross-section with calipers, not a ruler Inch and metric sizes are often within a fraction of a millimetre of each other, and a near-miss leaks or extrudes.
- Static vs dynamic service
- Dynamic (reciprocating or rotating) seals need abrasion-resistant compounds and lower squeeze than static seals A seal that works in a static flange can wear out quickly on a moving rod or shaft.
- Temperature and pressure range
- Confirm continuous temperature rating covers the system; above roughly 1,500 psi or with large clearance gaps, consider harder durometer or backup rings Heat degrades elastomers and high pressure extrudes soft seals into the clearance gap.
- Hardness (durometer)
- 70 Shore A is the general default; 90 Shore A for high pressure or extrusion-prone grooves Too soft extrudes, too hard fails to seal at low pressure or on rough surfaces.
Brands that matter
- Parker: Reference O-ring and seal maker; its O-Ring Handbook is the standard sizing and groove design guide.
- Trelleborg Sealing Solutions: Broad range of O-rings and hydraulic rod/piston seals for industrial use.
- Freudenberg: Major OEM seal manufacturer covering O-rings, lip seals and specialty compounds.
- SKF: Radial shaft lip seals and bearing-related sealing products.
- Inpro/Seal: Long-established bearing isolator specialist.
What to avoid
- Unbranded assortment kits with no stated compound for fuel, hydraulic or pressure-critical service
- Reusing old seals after disassembly
- Silicone seals in dynamic or abrasive applications
- EPDM in contact with petroleum oils or grease
Questions
Is Viton different from FKM?
Viton is a brand name for FKM fluoroelastomer; generic FKM seals use the same polymer family, though grades vary.
Should I replace a lip seal with a bearing isolator?
On pumps and motors with frequent lip seal failures, a non-contact bearing isolator usually lasts much longer, but it must fit the housing bore and shaft exactly.