US Patent 9651067 Hydraulic system with a dynamic seal

A system can include one or more valve arrangements with a working chamber to receive a working fluid at a first pressure, and a control chamber to receive fluid at a second pressure. A dynamic seal can be disposed on a land of a valve element. The valve arrangement may include a sleeve against which the dynamic seal is slidably engaged. The valve element may include a check stem. A pressure compensating system may be in communication with bores formed in with the valve element. A pressure system to monitor dynamic seal wear may be in communication with the control chamber of the valve arrangement.