Df Type
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Best DF Type Seal for machines at affordable prices
Also known as HDDF mechanical face seal, DF heavy-duty duo cone seal comprises a pair of diamond-shaped elastomers mounted on two identical lapped metal seal rings. The L-shaped profile of the contact interface secures and stabilizes the seal group within the housing cavity. When in operation, the elastomers provide requisite torque and axial loads to perform a reliable face-seal function.
Application and Design Features of DF Type Seal
DF type seal excels in heavy-duty application. They serve to protect ground and underground earthmoving equipment from extensive vibration and contamination. This type of seal is the top choice for off-road operations including mining equipment, screw conveyors, sprockets and crop harvesters.
Similar to the DO-type, the DF-type relies on the elasticity of the elastomers to enable the seal group to seat stably within the housing and achieve a face-to-face sealing function. The diamond-shaped elastomers, compared to standard O-rings, offer a greater deformation capacity, allowing for greater axial and radial displacement to withstand complex and rough operating environments.
Major difference between DO Type and DF Type
Diamond-shaped Elestomers
The DF type seals feature elastomers with a diamond-shaped cross section as opposed to O-rings used in the DO type.
Lower Circumferential Speed
As DF type has a greater deformation range than the DO type, it provides heavier axial load on the sealing faces. Therefore, the sealing faces are subject to higher contact pressure, which limits the maximum circumferential speed under 2m/sec, while the DO type operates at a maximum speed at 3~4m/sec.
Severer Operation Conditions
Compared with the DO type, DF type seal offers stronger sealing force and greater compensation capacity. This design provides improved protection against forced ingress of mixed solid and liquid contaminants in off-road operations.
Frequently Asked Questions on DF Type Seals
Q1. What differs DF-type duo cone seals from the DO-type in terms of application?
1, DF-type duo cone seals offer stronger sealing pressure and lower peripheral speed than the DO type. They are more resistant to forced ingress of abrasive contaminants for their extended compensation capacity.
2, This high-sealing-pressure design is particularly suited for significantly arduous applications where DO-type seals may fail under extreme external physical stress.
Q2. Is maintaining DF-type duo cone seals a challenge?
Not at all, DF-type duo cone seals are designed to be low-maintenance. However, regular checking on the transmission oil level is required to ensure the seals rotate smoothly，keeping them safe from dry running and cold welding. Normally, it is necessary to have a minimal oil level of 1/3 of the seal inside diameter.
Q3. What is the regular service life of DF-type duo cone seals?
The regular service life of DF-type seals depends on their working conditions. Under normal use, they typically last out several years. In extreme environments, however, the seals are likely to experience a shorter service life due to excessive operational and thermal stress.
Q4: Are DF-type duo cone seals appropriate for all machinery?
No. DF-type duo cone seals are distinctively designed for heavy-duty machinery. Compared to the DO type, they have a narrower range of application, mainly for applications involving high loads, abrasive, solid contaminants. Typical applications include agricultural machinery, screw conveyors and so forth. It is essential to ensure the seals properly matching the specific equipment in accordance with technical specifications.
