Hebei Hankai high temp oil seal


oil seal for rotating shaft.
A manhole cover is a removable lid over an opening to a man-made hole large enough for a person to pass through i.e. a manhole. For security reasons a cover keeps unauthorised people out and for safety reasons it prevents anyone (or anything) from falling in. These types of covers are typically used to safely and securely restrict entry to foul and surface water drainage systems, and other underground chambers, that require worker access for maintenance purposes. They are often made from cast iron, ductile iron, galvanised steel, concrete or even a combination of several of the above.
In recent years, the threat of intentional vehicular attacks has also necessitated a reevaluation of urban safety measures. High-profile incidents around the world have demonstrated how vehicles can be weaponized against innocent bystanders. In response, cities have increasingly adopted stronger bollard designs—a trend toward more robust materials, such as reinforced concrete and steel, which can withstand significant impacts. These reinforced bollards serve as formidable deterrents against potential attacks, ensuring that public spaces remain safe for all visitors.
bollard barrier
