Is it necessary to calibrate and certify the portable electrode quivers, rated for 250W @ 48 - 75VDC and fed from the welding power, used for the SMAW applications, as one of our clients is insisting for it?

We have about 1,500 quivers and being used for the last 25 years without any such calibration/ certification, considering that it is a tool for the welders to keep the processed/ hot electrodes transferred from the nearby holding ovens and to retain its temperature by adding certain heat input. The double wall type quiver has no thermal insulation, the heating element is attached into the bottom plate with a heat sink, the thermostat rated for 30 - 120 Deg.C is controlling the heat sink temperature and the heat is transferring by conduction. It cannot provide a stable temperature, as a result of ambient variation, voltage variation (ARC voltage and OCV) and quantity & temperature of the electrode being stored.

Considering their design, application and our experience, we think, there is no meaning in spending extra efforts for calibration/ certification activities other than inspection/ maintenance for ensuring the physical integrity and functionality.

Please review the above and comment. If calibration is required, what will be the acceptance criteria for the subject quivers used to handle the carbon steel low hydrogen electrodes (E 7018-1, E7018, E7018-1, E7028 etc.), transferring from the nearby holding ovens at 120 - 150 Deg.C?

The primary code that we used is AWS D1.1. The table 5.1 gives the exposure limits and stating that the heated quivers are not mandatory. however, it does not state the minimum temperature (or the temperature to be maintained above the ambient) that the electrode can expose before the welding.