Results and Data

The –2 (1/8 inch) size failed to complete the impulse test. All –2 plugs had structural failures and did not successfully complete the one million cycle test (see Appendix B). The structural failure occurred at the fitting o-ring cross section to the outside of the hex pattern of the fitting. All other sizes, excluding the –2 size, did successfully pass the impulse testing. All of the EPCO anodized aluminum plugs passed the proof and burst to the above stated specifications.

The final torque values to pass the impulse, proof and burst for the stated Zero-Leak Gold Plugs are listed in Table 2.

Table 2: Aluminum Zero-Leak Gold® Final Torque Values.

Table 3: Aluminum Zero-Leak Gold® Proof, Burst and Removal Torque data.

When the impulse testing was successfully finished each plug was removed from the manifold. Removal Torque values were recorded and listed in Table 3. The structural failure mode listed was a failure that occurred at the fitting o-ring cross section to the outside of the hex pattern of the fitting. This failure caused the plug to crack from the O-ring groove to the inside of the fitting causing the failure (see pictures in Appendix B). There was an unknown black residue around each plug upon the completion of the impulse test. No leaks were observed and the residue was sent to a lab to determine what the substance was.

The samples were sent to SF Analytical in Milwaukee for material analysis. The final results were inconclusive; no seal material could be identified from the samples. The client requested all plugs be pressurized beyond the 4:1 requirement (12,000 psi) and continue increasing pressure until failure of the fitting or limitations of the equipment are reached. The proof test results are also listed in Table 3 with the burst test results.