6.2 Pumping considerations Since the rate of separation depends on the oil globule size it will be appreciated that any disintegration of oil globules in the oily feed to the separator should be avoided and this factor can be seriously affected by the type and rating of the pump used. Tests were carried out by a British government research establishment some years ago on the suitability of various pumps for separator feed duties(Double vane, Triple screw and Single vane6.2 Pumping considerations • Since the rate of separation depends on the oil globule size it will be appreciated that any disintegration of oil globules in the oily feed to the separator should be avoided and this factor can be seriously affected by the type and rating of the pump used. Tests were carried out by a British government research establishment some years ago on the suitability of various pumps for separator feed duties (Double vane, Triple screw and Single vane )