Characteristics and performance
The Hallite 847 wiper has been specifically developed for cylinders used in demanding, heavy-duty off-highway applications in dirty environments, such as earth-moving excavators. This double-lipped wiper incorporates a special venting feature to permanently relieve pressure build-up between the rod seal and wiper. This prevents pressure from ejecting the wiper without the need for an expensive vent hole in the gland.
The flap on the wiping lip is another special feature that covers the gland housing and prevents the water/slurry trap that is common with conventional wipers. The design minimises oil transfer out of the ram on the rod and prevents dirt, contamination, and moisture from entering the cylinder through the gland.
The standard range is made from high-performance Hythane® 371 polyurethane. The wiper is also available in other polyurethane grades, if required, potentially extending the operating conditions.