The booklet Seraphim is written by L. Steven Cheairs. This booklet does the same for Seraphim that the author’s booklet Cherubim are not Angels does for Cherub and Cherubim. It shows that Cherubim are symbols in visions or poetic devices to tell about God’s attributes. But they are not angels. Likewise the booklet Seraphim shows that Seraphim, living being, fiery serpents, are rivers of fire are in visions or poetic devices to tell about God sending His Holy Spirit out for judgment, trials, answers to prayer, anointing, bestowing gifts, as a Helper and such.
But they are not any type of angel.