Custom U-Cup Seal

Custom U-Cup Seal is made to the actual cylinder rather than to a fixed catalog size. Rod or piston dimensions, groove geometry, lip shape, compound, and the working medium can all be matched to the existing hardware. This is useful for non-standard grooves, obsolete replacement parts, hydraulic presses, mobile equipment, automation actuators, and other fluid-power systems where an off-the-shelf seal does not fit the job.

Groove-Matched Interference for Non-Standard Cavities

The lip geometry is set from the actual rod or bore, groove width, and clearance. That lets the seal develop the required interference in the existing cavity instead of forcing a standard profile into a space it was not designed for. On older cylinders and one-off equipment, this can prevent both leakage and unnecessary running drag.

Direct Replacement Without Reworking the Cylinder

For obsolete or non-standard equipment, the seal can be built around the original rod, piston, and groove. The surrounding metal parts do not need to be redesigned simply to accept a catalog seal. This is especially useful in repair work where re-machining the gland or piston would extend downtime.

Anti-Extrusion Support for Hydraulic Loads up to 40 MPa

Custom hydraulic versions can be configured for service up to 40 MPa when the material, lip support, and clearance are suitable. If the extrusion gap is relatively wide, the heel and any back-up arrangement need enough support to keep the seal from being pushed into the gap. This reduces nibbling, edge cuts, and other pressure-related damage.

Development Basis

2D drawings, 3D models, groove measurements, or physical samples.

Installation Version

Rod-seal or piston-seal configuration; metric or inch dimensional system.

Color and Model Mix

Different colors or models can be combined within one MOQ.

Different fluid media and operating temperatures demand specific elastomer formulations. We select materials based on your system's actual working conditions:

Before molding, the rubber or polymer lot is checked for compound identity and the physical properties specified for the order. Shore A hardness is verified, and specific gravity or tensile properties can also be checked when required. The batch is released only after those material checks are complete.

Inspection focuses on the dimensions that affect sealing, not just the outside size. Mold cavity dimensions, lip thickness, ID, OD, section height, and the parting-line position are measured with calibrated equipment. Flash or dimensional drift at the active lip is treated as a functional defect.

Finished parts are checked dimensionally and receive 100% visual inspection before packing. The inspection covers the lip edge, porosity, flow marks, cuts, deformation, and other visible defects. Material-lot and production references are kept with the batch for repeat-order traceability.

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