Casual Treatment of Seal Welds

The minimum heat input requirements imposed by AWS D1.1may be violated when the seal weld is made. Table 5.8 of that code prescribes certain minimum sizes of welds that must be maintained, regardless of the level of loading, in order to ensure that adequate heat input is achieved when the weld is made. The size of the seal weld may not be specified, resulting in a weld that would otherwise be disallowed by Table 5.8. It is still important that good welding practices be followed when seal welds are made, including adherence to the minimum fillet weld size. Failure to do so may result in weld cracking or incomplete fusion defects.

The welder who is charged with the responsibility of making a seal weld may approach it in a very casual manner, as might the welder’s supervisor. The welder should have the same qualifications as the welder charged with the responsibility for making a similar weld that would have a structural purpose. The welding procedures, including the selection of the electrode and the required preheat level, are deserving of the same attention as a weld that transfers calculated loads. The claim “It is only a seal weld” is often a prescription for problems.

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