The 318 Series Heavy-Duty, Double-Acting Wiper is one of the most popular mill-duty wipers in the steel industry. It includes a reinforced PTFE filled scraper ring and two energizing O-rings. The design incorporates a unique umbrella feature that wraps around the face of the cylinder to create an impenetrable barrier as well as an inner sealing lip to remove any oil film from the rod as it cycles. The O-rings individually energize the two wiper lips. In most applications, a pressure relief port between the wiper and the rod seal is recommended.