I have never heard of using a submersible pump for liquid sulfur. You may be using the term differently than I am familiar with. In a submersible, the motor would be submerged in the product and only electrical wiring and the discharge line would come up to the surface of the pit. You may be thinking of a vertical volute pump (sometimes called a wet pit pump). This would have the motor on the surface with a shaft running down to the impeller at the bottom of the pit. We only use vertical volute pumps in sulfur loading. They are not API pumps. The manufacturer of our pump specializes is sulfur pumps, Charles Lewis Company. They have worked well for us. But be careful about a few things. You will have less trouble with lower speed pumps (1800 rpm is much better than 3600 rpm). Cast iron bushing and sleeves work well, but they offer some other materials that should be considered. Lastly, make sure the steam for the jacketing is at the optimum pressure and temperature. If the steam is too hot, it can lead to pump failures that can start sulfur fires.
