The 315 Series Heavy-Duty, Double-Acting Wiper is one of the most popular heavyduty wipers. It includes a reinforced PTFE filled scraper ring and one energizing O-ring. The design incorporates a wiping lip to prevent contamination from entering the cylinder and an inner sealing lip to remove any oil film from the rod as it cycles. The O-ring energizes the two wiper lips. In most applications, a pressure relief port between the wiper and the rod seal is recommended.