Double Lip TB Rubber Oil Seal

The Double Lip TB Rubber Oil Seal is a metal-cased radial shaft seal with a spring-loaded primary lip and a secondary exclusion lip. It is used in agricultural equipment, construction and mining machinery, industrial gearboxes, conveyors, pumps, and electric motors where the shaft area is exposed to dust, grit, mud, or water splash while lubricant must remain inside the housing.

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Product Introduction

Product Overview

Core Advantages

≤0.03 MPa Low-Pressure Duty

The standard double-lip TB works in low-pressure rotary service up to 0.03 MPa. In vented gearboxes, conveyors, pumps, and motors, this keeps the main lip within a conventional lubricant-retention load while the auxiliary lip handles external contamination.

Primary Lip + Auxiliary Exclusion Lip

The primary lip is spring energized for fluid retention, while the second lip provides a separate barrier to cement dust, sand, mud, and splash. In crushers, harvesters, conveyors, or outdoor drives, this layout reduces direct contaminant loading on the lubricated main seal track.

Ra 0.2–0.8 µm Counterface Requirement

The recommended shaft roughness is Ra 0.2–0.8 µm. During continuous rotation, controlling the seal track within this range reduces abrasive lip wear and helps keep the thin lubricant film needed at the main sealing edge.

Material Performance Matrix

Compound selection is matched to specific thermal, chemical, and environmental exposure limits:

Material	Operating Temperature	Key Chemical / Mechanical Properties	Primary Applications
NBR (Nitrile)	-40°C to +100°C	High tensile strength, excellent resistance to petroleum-based oils and greases.	General industrial machinery, gearboxes
HNBR	-40°C to +150°C	Enhanced resistance to heat, ozone, and high-load mechanical stress.	Heavy-duty drives, automotive components
FKM (Viton®)	-20°C to +200°C	Superior resistance to synthetic lubricants, aggressive chemicals, and elevated temperatures.	Chemical processing, high-temp industrial equipment
Silicone	-60°C to +200°C	Outstanding low-temperature flexibility and weather aging resistance.	Food-grade machinery, low-temp electronics
EPDM	-50°C to +150°C	Excellent resistance to polar fluids, steam, water, and phosphate esters.	Water pumps, fluid handling systems

Product Specifications

Seal Design	TB Type (Double Lip with Garter Spring).
Hardness Range	60 to 90 Shore A (customizable per application load).
Pressure Limit	Designed for low-pressure applications (<= 0.03 MPa).
Dimension Standards	Metric and Inch sizes available (Custom diameters and widths built to drawing or sample).
Shaft Requirements	Recommended surface finish of Ra 0.2 to 0.8 um with appropriate shaft hardness to maximize service life.

Customization

Dimensions

Metric, inch, and non-standard shaft diameter, metal-case OD, and width can be made to a drawing or sample.

Material & Hardness

NBR, HNBR, FKM, VMQ, or media-specific compounds can be selected, with hardness from 60 to 90 Shore A where applicable.

Spring & Case

Carbon-steel or stainless-steel garter spring and project-specified metal-case material or surface finish are available.

Quality Control

Before production, the elastomer, metal cases, and springs are checked for material identity and visible condition. If the order specifies hardness, tensile properties, or another compound criterion, that requirement is verified for the selected material batch.

After molding and assembly, metal OD, ID, width, both lip edges, and spring seating are compared with the drawing. The process inspection focuses separately on the fluid-retention lip and the exclusion lip so damage to one functional edge is not treated as a general cosmetic defect.

Final inspection verifies part number, dimension code, material identification, visible condition, quantity, labels, and carton condition. Accepted and rejected parts remain separated before packing, and third-party inspection is available when specified in the order.