The Hallite 842 rod wiper is designed to prevent the ingress of foreign particles and moisture into the cylinder. The profile has been specially developed for harsh environments, in particular the longall mining industry.
The special feature is the flap on the wiping lip which covers the gland housing, preventing the water/slurry trap so common with conventional wipers and thus ingress of contamination around the outside of the wiper. The internal ribs on the inside diamter prevent the possibility of pressure trapping between the gland seal and the wiper and ensure correct support and guidance of the wiping lip, even in cases of high eccentricity as can occur between the outer stage gland and the inner cylinder of a roof support leg.
The Hallite 842 is manufactured in Hallite’s high performance polyurethane Hythane® 181. The material has excellent compression set characteristics, excellent wear and abrasive resistance, proven compatability with HFA (95/5) fluids, as used in longwall mining equipment, and with mineral oil.
A number of sizes, indicated by *, do not have an interference fit between the outside diameter of the wiper and the wiper housing bore ØD1. They float on the retaining lip.