A useful semiconductor O-ring inquiry identifies the seal, its working environment and the evidence needed for acceptance. This checklist helps equipment manufacturers, maintenance teams and local distributors prepare a request even when the original part information is incomplete.
Separate material, geometry and operating duty
| Information | What to provide | Why it matters |
|---|---|---|
| Material | Manufacturer and exact compound grade, or mark unknown | FFKM names a material family, not a complete compound specification |
| Finished size | Inner diameter × cross-section, units, tolerances, size code and drawing revision | A material grade does not identify a finished ring |
| Groove or mating parts | Drawing, groove dimensions and relevant surface requirements | Nominal ring dimensions alone do not establish installed fit |
| Sealing position | Equipment model if known, chamber/valve/line position, static or dynamic duty | A general application label is not an OEM-approved part mapping |
| Process media | Chemicals or gases, mixtures, concentration and cleaning exposure | Compatibility depends on the actual media and conditions |
| Temperature and pressure | Normal and peak temperature with duration, pressure or vacuum and cycles | A catalog endpoint is not a service-life guarantee |
| Plasma | Direct or remote exposure and non-confidential process conditions | A broad plasma-resistance statement does not cover every process |
| Acceptance evidence | Required cleanliness, leakage, particle, outgassing, traceability and packaging criteria | Catalog descriptions may omit the buyer's qualification limits |
| Purchasing scope | Quantity per size, delivery location, requested date and repeat demand if applicable | Quote and supply terms depend on the defined specification |
Start with the information you have
If you only have an old ring, send photographs and any package label, drawing or purchase record that can identify it. Mark measured dimensions as measurements of a used part. Service exposure may have changed its shape, so do not silently treat those dimensions as the original drawing specification.
If you know a material grade but not the size, send the grade and describe the sealing location. If you know the equipment and old part number but not the material, preserve the exact identifiers and ask for the applicable drawing and compound documentation. Unresolved fields should remain unknown until verified.
A practical request template
- Buyer role: equipment manufacturer, end-user maintenance team or local distributor.
- Original manufacturer / material grade / part number: known values or unknown.
- Size code or inner diameter × cross-section, units, tolerances and drawing revision.
- Sealing position, static/dynamic duty and groove information.
- Media, concentration, operating/peak temperature and duration, pressure/vacuum and plasma exposure.
- Required quantity by size, destination, requested date and repeat demand if relevant.
- Required evidence: material documentation, traceability, cleaning/packaging and agreed acceptance tests.
- Requested outcome: same specification, candidate selection, or an alternative to evaluate.
For a distributor, a size-by-size quantity list is more useful than a request for a generic price for O-rings. State whether the inquiry concerns a one-off maintenance requirement or recurring customer demand. Avoid sharing confidential end-customer process details in a public reply; use the private inquiry channel for the necessary commercial discussion.
How to assess a proposed alternative
Build a comparison with a source and a test condition for each parameter. Mark each result as supported, different or unknown. Similar color, hardness or an overlapping temperature range does not establish interchangeability.
For example, the MORISEAL table lists 6002UP at 80±5 HA and 5802SP at 75±5 HA. Their compression-set values are 19% and 16% at 200 °C / 70 h. Both list a 0 to 300 °C temperature range and a water-vapor/oxygen/ozone application direction. Those shared entries and differences define questions to resolve; they do not prove a replacement is acceptable in the customer's equipment.
Ask the supplier and equipment owner to define the applicable fit, material-response, leakage and contamination checks. Keep any approval tied to the actual drawing, operating window and tested configuration. This article does not provide a qualified alternative for an unspecified OEM tool.
What the manufacturer size index does and does not provide
MORISEAL's site lists P, AS568, G, AN6227, GS, AN6230, V, S, VS, JASO, GM, KS, SS and ISO size families, along with custom sizes. Supply the exact size designation and drawing where possible. A family name alone is not a dimension, tolerance or availability commitment.
The manufacturer's groove calculator can help structure dimensional inputs. Its output still depends on correct input values and an applicable material choice; do not invent a squeeze ratio or accept a calculator result as process qualification.
Original material data:
https://www.moriseal.com/en/Product/index.aspx
Size inquiry:
https://www.moriseal.com/ProductCenter/index.aspx
Manufacturer groove calculator:
https://www.moriseal.com/Calculator/index.aspx
Next step
Review the documented MORISEAL material-series entries:
https://store.mst-sg.com/store/semiconductor-seals-o-rings
Manufacturers and local distributors can use the inquiry action on this page with the known information. The quotation should confirm the selected grade, dimensions, quantity, documentation, supply and lead time before an order is agreed.
MST Engineering editorial checklist. Source review: 2026-10-19. No price, stock, equipment approval or cross-brand equivalence is inferred from this reference.
Product data and related guidance
Compare the documented material grades in the selection guide:
https://store.mst-sg.com/community/t/4-semiconductor-ffkm-o-ring-selection-moriseal-morisz-grades-a
Product pages for the comparison example:
Morisz 6002UP — Product data and quotation
https://store.mst-sg.com/store/semiconductor-seals-o-rings/MORISZ-6002UP-RFQ
Morisz 5802SP — Product data and quotation
https://store.mst-sg.com/store/semiconductor-seals-o-rings/MORISZ-5802SP-RFQ