Why Choose a DO Type Floating Seal?

The DO Type Mechanical Face Seal is one of the most widely used mechanical face seal designs for heavy-duty rotating equipment.

• ◆ Protection against abrasive contamination – the metal face sealing system helps isolate bearings and lubricated components from mud, sand, dust and water.

• ◆ Reliable lubricant retention – closely matched sealing faces help reduce loss of oil or grease from the protected housing.

• ◆ Wear-resistant metal sealing interface – designed for equipment exposed to continuous contamination and abrasive operating conditions.

• ◆ Self-centering capability – the elastomer O-rings support and position the metal rings while allowing the sealing system to accommodate limited movement and eccentricity.

• ◆ Simple mechanical structure – two metal seal rings and two elastomer rings form a robust sealing arrangement suitable for heavy-duty equipment.

• ◆ Long-term sealing for difficult environments – particularly suitable where reliability and reduced maintenance are more important than the use of a conventional lip or shaft seal.

For applications where installation space, housing design or assembly requirements differ, ZHONO also supplies DF Type Mechanical Face Seals.

Materials for Heavy-Duty Operating Conditions

Material selection is an important part of floating seal performance, especially when equipment is exposed to abrasive particles, temperature changes and long operating cycles. ZHONO floating seal metal rings are available in high-chrome alloy cast iron, with hardness stated at 60–72 HRC.

For detailed metal and elastomer information, see our Mechanical Face Seal Materials.

Typical Applications of DO Type Floating Seals

DO type mechanical face seals and floating oil seals are particularly suitable for slow- to moderate-speed rotating systems operating in contaminated environments.

Typical equipment includes:

Construction Machinery

Used in excavators, bulldozers and other tracked equipment where undercarriage and drivetrain components are continuously exposed to soil, mud, gravel and water.

Typical sealing positions may include:

• ◆ Track rollers

• ◆ Idlers

• ◆ Final drives

• ◆ Axles

• ◆ Gear housings

Mining Equipment

Mining equipment operates in highly abrasive environments containing mineral dust, slurry and debris. Heavy-duty metal face seals help protect lubricated rotating components against contamination.

Applications can include:

• ◆ Mining vehicles

• ◆ Conveyor systems

• ◆ Coal mining machinery

• ◆ Drive units

• ◆ Transmission systems

Agricultural Machinery

DO floating seals are also suitable for agricultural machines operating in soil, mud, crop residue and outdoor moisture.

Typical equipment includes:

• ◆ Tractors

• ◆ Rotary cultivators

• ◆ Harvesting machinery

• ◆ Agricultural axles

• ◆ Drive assemblies

Tunneling and Heavy Industrial Equipment

Mechanical face seals can also be applied in equipment where contamination resistance and long maintenance intervals are important, including tunnel boring machinery, heavy conveyors and other industrial rotating systems. Explore additional examples in our Mechanical Face Seal Applications.

Quality Control for Mechanical Face Seals

For industrial buyers, mechanical face seal quality depends on more than dimensional accuracy. Material composition, hardness, sealing-face condition and dynamic performance all influence service reliability.

ZHONO supports mechanical face seal quality verification with dedicated testing equipment.

Our testing capabilities include:

Dynamic Lifetime Testing

Testing equipment can simulate operating conditions and evaluate whether the seal maintains sealing performance at specified speed and temperature.

Material Composition Analysis

A spectrometer is used to analyze the composition of the metal sealing ring and help verify material consistency.

Rockwell Hardness Testing

Metal ring hardness is checked because wear resistance and sealing life are closely related to material hardness.

Metallographic Examination

Metallographic testing helps evaluate the internal structure of the metal material and provides additional information about its physical and mechanical properties.

Correct Installation Matters

Even a correctly selected floating seal can suffer premature failure when the housing, O-ring or sealing face is contaminated or incorrectly installed.

Before installation:

• ◆ Clean the housing groove thoroughly.

• ◆ Make sure there are no burrs or contaminants.

• ◆ Keep the elastomer O-ring free from twisting.

• ◆ Do not apply oil or grease to the O-ring simply to make installation easier.

• ◆ Make sure the sealing faces remain clean and undamaged.

• ◆ Check that both seal halves are installed evenly and correctly aligned.

A dedicated installation tool helps position the DO floating seal and O-ring evenly in the housing and reduces the risk of distortion during assembly.

See our complete Floating Seal Installation Guide and Tools before installation.

Why Source DO Type Mechanical Face Seals from ZHONO?

ZHONO focuses on the development, manufacture and technical support of mechanical face seals and floating seals for heavy-duty machinery.

Our product range includes DO, DF, XY and YY mechanical face seal designs, allowing equipment manufacturers, replacement-parts suppliers and industrial distributors to source different sealing configurations according to their application requirements.

Specialized Mechanical Face Seal Experience

ZHONO focuses specifically on mechanical face sealing technology rather than maintaining a broad general-purpose seal catalog. Our experience covers product design, manufacturing, application selection and installation support.

Multiple Material Options

High-chrome alloy cast iron metal rings and multiple elastomer options including NBR, HNBR, VMQ and FKM allow seal configurations to be selected according to different working environments.

Product Testing Support

Dynamic lifetime testing, material analysis, hardness inspection and metallographic examination provide additional control over the properties that influence mechanical face seal performance.

Technical Selection Support

If the required DO seal number is unknown, send us your seal dimensions, equipment information, drawing or application requirements. Our team can help identify the appropriate mechanical face seal configuration.

DO Type vs. DF Type Mechanical Face Seal

DO and DF mechanical face seals use the same basic metal-face sealing principle, but they use different secondary elastomer designs.

If your application uses a trapezoidal secondary sealing element, view our DF Type Mechanical Face Seal.