Seat Seals: Hardness 70-90 Shore A (elastomers)

Component Specifications

Definition

Seat seals are annular sealing elements installed in sanitary ball valve assemblies that create a leak-tight seal between the rotating ball and stationary valve body. These components are critical for maintaining system integrity in sanitary applications where contamination prevention, cleanability, and corrosion resistance are essential. They are designed to withstand repeated cycling, temperature variations, and chemical exposure while maintaining sealing performance.

Working Principle

Seat seals operate on the principle of elastic deformation and compression sealing. When the ball valve is closed, the rotating ball compresses the seat seal against the valve body, creating a tight seal through controlled deformation. The seal's geometry and material properties allow it to maintain contact pressure while accommodating minor surface imperfections and thermal expansion. In sanitary applications, the seal must also facilitate clean-in-place (CIP) and steam-in-place (SIP) processes without degradation.

Materials

Food-grade elastomers (EPDM, FKM/Viton, Silicone) meeting FDA 21 CFR 177.2600, USP Class VI, or 3-A Sanitary Standards; PTFE for chemical resistance; reinforced polymers for high-pressure applications; all materials must be non-toxic, non-absorbent, and resistant to cleaning chemicals and sterilization.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Hardness	70-90 Shore A (elastomers)
Cleanability	CIP/SIP compatible, crevice-free design
Surface Finish	Ra ≤ 0.8 μm (32 μin) contact surfaces
Compression Set	<20% after 24h at 70°C
Pressure Rating	Up to 10 bar (standard), 16 bar (high-pressure designs)
Temperature Range	-20°C to 150°C (standard), up to 180°C (high-temp variants)

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

ISO 5211, ISO 5752, DIN 3230, 3-A Sanitary Standards 74-00, FDA 21 CFR 177.2600

Parent Products

This component is used in the following industrial products

Sanitary Ball Valve Assembly

Hygienic ball valve assembly for precise flow control in beverage processing lines

View Product Details

Engineering Analysis

Risks & Mitigation

Seal degradation from chemical exposure
Compression set leading to leakage
Thermal expansion mismatch
Improper installation causing extrusion
Microbial harborage in damaged seals

FMEA Triads

Trigger: Chemical attack from cleaning agents
Failure: Seal swelling, cracking, or loss of elasticity
Mitigation: Select chemically compatible materials; validate with chemical resistance charts; implement proper cleaning concentration/temperature controls

Trigger: Excessive compression during installation
Failure: Permanent deformation, reduced sealing force, shortened lifespan
Mitigation: Use torque-controlled installation tools; follow manufacturer torque specifications; inspect seals post-installation

Trigger: Thermal cycling beyond material limits
Failure: Cracking, hardening, or compression set
Mitigation: Select materials with appropriate temperature range; implement gradual temperature changes; monitor operating temperatures

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

±0.1mm on critical dimensions, surface roughness Ra ≤ 0.8μm, no visible defects per visual inspection standards

Test Method

Helium leak test (<1×10⁻⁶ mbar·L/s), pressure decay test (≤0.1 bar drop in 5 min), material certification per FDA/3-A, extractables testing per USP <661>

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Seat Seals

1 company lists this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

JST Seals

Guangzhou, Guangdong, CN

Also makes: Hydraulic Cylinder, Hydraulic Piston, Piston Rod & Seal and 9 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Cryogenic Butterfly Seat Seals”
View source page ↗ jst-seals.com · checked 2026-09-03

View profile Send enquiry

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review

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Frequently Asked Questions

How often should sanitary seat seals be replaced?

Replacement intervals depend on operating conditions: typically 12-24 months for continuous service, or when leakage exceeds 0.1% of flow rate. Monitor for compression set, cracking, or chemical degradation.

Can seat seals handle steam sterilization?

Yes, when made from appropriate materials like EPDM or FKM rated for SIP processes (typically 121-135°C for 20-30 minutes). Verify manufacturer specifications for specific temperature and duration limits.

Are seat seals interchangeable between valve brands?

Not universally. While dimensional standards exist, seal geometry, compression characteristics, and material formulations are often brand-specific. Always consult compatibility charts or manufacturer recommendations.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Seat Seals