Rod Seals
A rod seal is a sealing component used at the reciprocating rod (shaft) of hydraulic and pneumatic cylinders to prevent the working fluid inside the cylinder from leaking to the outside. It is installed in a groove on the housing side, and its lip or contact surface is pressed against the rod surface to seal. Types include U-packings, types with a built-in O-ring to compensate for squeeze, PTFE types that apply contact force with a spring, and chevron packings that stack multiple pieces. For high-pressure use, a backup ring is combined to suppress extrusion into the clearance. Materials include PU (polyurethane), rubbers such as NBR, and PTFE. Besides hydraulic cylinders of construction machinery and presses, they are also used for valve stems.
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Rod Seals
Rod Seal (S04-P/S05-P/S05-R/S06-P/S06-R/S07-P/S07-F/S08-P/S08-PE/S08-R/S09-E/S09-D)
Rod seals for hydraulic and pneumatic cylinders, available in different materials such as ECOPUR, Ecorubber, and Ecoflon, supporting single-acting and double-acting applications.
SKF
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Rod Seals
S04-P Rod Seal
Model: S04-P
High-pressure hydraulic rod seal with built-in O-ring and square backup ring.
SKF
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Rod Seals
S03-SX Rod Seal
Model: S03-SX
Single-acting PTFE rod seal with an improved spring groove. Elgiloy spring also available.
SKF
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Rod Seals
S03-S Rod Seal
Model: S03-S
Single-acting PTFE rod seal with built-in helical spring. Excellent chemical and heat resistance.
SKF
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Rod Seals
S03-F Rod Seal
Model: S03-F
Single-acting PTFE rod seal with reduced frictional resistance. Compatible with a wide temperature range.
SKF
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Rod Seals
S03-P Rod Seal
Model: S03-P
Hydraulic single-acting rod seal with built-in O-ring, compatible with a wide temperature range.
SKF
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Rod Seals
S02-S Rod Seal
Model: S02-S
Buffer seal with integrated backup ring for special housings.
SKF
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Rod Seals
S02-R Rod Seal
Model: S02-R
Hydraulic rod seal with square backup ring offering excellent chemical and heat resistance.
SKF
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Rod Seals
S02-RD Rod Seal
Model: S02-RD
Hydraulic rod seal with trapezoidal back-up ring, offering excellent chemical resistance and heat resistance.
SKF
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Rod Seals
S02-PD Rod Seal
Model: S02-PD
High-pressure hydraulic rod seal with a trapezoidal active backup ring.
SKF
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Rod Seals
S02-P Rod Seal
Model: S02-P
High-pressure hydraulic rod seal with a square active backup ring.
SKF
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Rod Seals
S01-R Rod Seal
Model: S01-R
Rod seal for SKF Ecorubber-based materials, offering excellent chemical resistance and heat resistance.
SKF
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Rod Seals
S01-P Rod Seal
Model: S01-P
A single-acting rod seal that combines high sealing performance and oil film retention across a wide temperature range.
SKF
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Rod Seals
Rod Seal (S10/S13 Chevron Packing)
Model: S1012 / S1315
Single-acting rod seal for heavy industrial hydraulic equipment and presses. Suitable for worn rods, with split-type available.
SKF
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Rod Seals
Rod Seal (S09 Single-Acting/Double-Acting Piston Seal, O-Ring Combination PTFE)
Model: S09-E / S09-P / S09-D
Single-acting and double-acting piston seal for civil engineering machinery and high-load hydraulic equipment. Combines an O-ring with PTFE (TPU seal), featuring pressure and impact resistance and long service life.
SKF
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Rod Seals
Rod Seal (S01 Single-Acting Piston Seal, Lip Type (U-Cup) Seal, Compact Seal)
Model: S01
Single-acting piston and rod seal for small and standard hydraulic equipment. Offers high stability within the housing, excellent sealing performance and good back-pumping performance.
SKF
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Rod Seals
Rod Seal
A range of seal products used at the rod section of hydraulic and pneumatic cylinders. Listed in the table of contents of this document, but the body text is not included in the excerpt.
SKF
How to choose Rod Seals
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1. Match rod diameter and groove dimensions
A seal is specified by the combination of applicable rod diameter and installation groove dimensions. The applicable rod diameter of listed products is 5 to 1000 mm. When fitting into an existing groove, check on the drawing that, in addition to the rod diameter, the groove width and groove bottom diameter match the standard combination.
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2. Verify cross-section and groove width
Cross-section dimension (c/s, radial thickness) corresponds to the groove depth, and groove width L corresponds to the axial length. The listed range is 2.45 to 20 mm cross-section and 2.2 to 50 mm groove width. If dimensions do not match, insufficient squeeze causes leakage, and excessive compression causes early wear.
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3. Maximum operating pressure and backup rings
The maximum operating pressure of listed products is 160 to 700 bar. At high pressure, the seal tends to extrude into the clearance and fail, so consider types with square or trapezoidal backup rings. Confirm that the pressure, including pressure surges (momentary pressure rises), stays within the upper limit.
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4. Select material by temperature and fluid compatibility
PU offers excellent wear resistance, while PTFE has high chemical and heat resistance and low friction. Rubber-based materials vary in oil and heat resistance depending on their compound. Operating temperature ranges differ by material, so select a material that suits the working fluid, such as hydraulic oil, water, or air, and the operating temperature.
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5. Check the upper limit of sliding speed
The maximum sliding speed of listed products is 0.5 to 10 m/s, which varies greatly by material and type. Use at high speed accelerates deterioration due to frictional heat. Check that the maximum cylinder speed is within the upper limit, and consider low-friction PTFE-based types for high-speed applications.
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6. Select seal type and operating method
Rod seals are basically single-acting types that receive pressure from one side. In high-pressure systems, there is a method of combining them with buffer seals. For large machines that are hard to install or have worn rods, chevron packings, which can be selected as split types, are suitable.
This guide was written by AI based on the listed products' documents and specification items. Check each manufacturer's documents before adopting.