Comparing Scavenge Vs. Purge Ports On Grippers

Every style of gripper is protected by either a shield or a seal, both of which are designed to prevent dirt, contaminants or lubricating grease from entering or exiting the interior of the gripper. It is these foreign bodies that can compromise the gripper’s performance, leading to costly malfunctions and breakdowns that can knock your workholding or pick-and-place applications offline.

Whether ingress or egress is allowed depends on the operating atmosphere in which the gripper will be used – either “dirty/contaminated” or “clean room”, while recognizing that a good clean-room product is a good dirty-room product, but not necessarily vice versa.

DESTACO OFFERS TWO DISTINCT WAYS IN WHICH CONTAMINANTS CAN BE KEPT FROM EITHER ENTERING OR EXITING THE INTERIOR OF GRIPPERS

Scavenge Port

• A scavenge port utilizes low-level vacuum pressure that draws air through a series of slots from outside the gripper into the internal mechanism. The negative air pressure that is created prevents dirt, contaminants or lubricating grease from exiting the gripper.
  
  
• This method of contaminant control makes scavenge ports ideal for clean-room applications since the clean air in the clean room is used to keep the dirtier air in the gripper at bay. This is important since any contaminants or grease that are allowed to enter the clean air can adversely affect the hygienic level of the clean-room application.

Purge Port

• A purge port operates in the opposite manner of a scavenge port. The purge port is located on the gripper’s body and has a channel to the internal mechanism, through which low-pressure, compressed air is drawn into the gripper in order to keep positive pressure inside the housing. The compressed air then flows through small ports preventing contaminants from entering into the gripper.
  
  
• Purge ports can also be outfitted with grease fittings that will purge dirty grease from the gripper’s interior and/or add new grease to the unit.
  
  
• Because purge ports are designed to prevent contaminants from being drawn into the gripper, they are very effective in dirtier or more contaminate-laden operating atmospheres.

For more information, contact our experts or browse our complete line of gripper products!