How to do pressure test of cylindrical Rubber Fender

How to do pressure test of cylindrical Rubber Fender ?

A full-scale static compression pressure test for large-size cylindrical rubber fender (CY type) has been successfully carried out using the factory’s self-owned 2000 Tons Rubber Fender Pressure Testing Machine, providing authoritative mechanical performance data for port and dock berthing projects worldwide.

Test Purpose

1. Measure real-time reaction force and deflection curve of cylindrical rubber fender under continuous compression load.

2. Calculate energy absorption capacity at rated compression deflection to verify compliance with technical specifications.

3. Evaluate structural rigidity and buffer performance to protect dock structures and vessel hulls during berthing operations.

4. Complete type test evidence for third-party surveyors including DNV, Lloyd’s Register, CCS and BV for export orders.

5. Validate rubber compound formulation and vulcanization quality, ensuring stable performance of mass-produced marine fenders.

6. Supply reliable test parameters for marine engineering designers for berth fender system selection.

 Test Equipment & Preconditions

- Test Equipment: 2000 Tons Hydraulic Pressure Testing Machine with high-precision force & displacement data acquisition system

- Specimen: Large cylindrical rubber fender (CY series)

- Ambient temperature: 23℃ ±5℃

- Standard compression speed: 70 mm/min

- Pre-treatment: The rubber fender was placed in the test laboratory for more than 12 hours to reach stable ambient temperature before testing.

 Complete Test Procedures

1. Pre-test Visual & Dimensional Inspection

Technicians inspected the fender surface for cracks, delamination and air holes. Outer diameter, inner diameter and effective length were measured and recorded.

2. Specimen Centering & Installation

The cylindrical rubber fender was vertically positioned on the rigid base platform inside the 2000-ton testing frame. The compression direction is consistent with actual on-site service condition. Upper and lower pressing steel plates remain parallel, and the specimen is aligned with the loading central axis.

3. System Zero Calibration

The force sensor and displacement sensor were reset to zero under no-load status; test parameters including compression speed and maximum target deflection were set on the control system.

4. First Pre-compression Cycle

The machine compressed the fender gradually up to rated deflection, held load for 3–5 seconds, then fully unloaded. This cycle eliminates rubber hysteresis effect and internal residual stress, and all data from this cycle will be discarded.

5. Recovery Interval

After full unloading, the specimen rested for 30 minutes to achieve sufficient elastic recovery.

6. Formal Compression Cycles (2nd & 3rd Test)

Two repeated formal compression tests were conducted with the same compression rate. Force and deflection data were recorded at fixed deflection intervals (10%, 20%, 30%…60% of original outer diameter). After reaching rated deflection, the equipment unloaded slowly.

7. Data Analysis & Acceptance Judgement

Average values of the 2nd and 3rd valid cycles were adopted. The force-deflection curve was plotted, and energy absorption was calculated via integral algorithm.

Energy absorption at rated deflection ≥90% of nominal value;

Maximum reaction force at rated deflection ≤115% of nominal value.

8. Post-test Inspection

The fender was examined after unloading to check surface cracking, separation and permanent deformation. The final test report was issued after all indexes passed inspection.

Full-scale compression testing on our 2000-ton testing rig guarantees that every large marine rubber fender supplied to overseas ports meets international classification society requirements. Reliable physical test data helps global clients reduce berthing risk and optimize dock investment.