Hydraulic Steering Nylon Tubing 3/8in.-25 ft. | Dometic Seastar HT5092 Seastar Hydraulic Steering Nylon Tubing 3/8in.-25 ft. | HT5092 25 ft. of 3/8 in. nylon hydraulic tubing for use with many small inboard & stern drive Seastar hydraulic steering systems. For use with Teleflex SeaStar 1.7 helms on stern drives and inboards with fitting kits 3/8 in. outside diameter 25 ft. length Not for use with SeaStar HC5332 cylinders Not for use on outboard hydraulic steering systems SEASTAR SOLUTIONS Hydraulic Steering Nylon Tubing can be used with Seastar 1.7 helms on stern drives and small inboards with fitting kit (except with HC5332 cylinder). Not to be used with outboard systems. Dometic SeaStar steering hoses are a custom multi-layered composite design, engineered specifically for our systems. They are designed to exceed SAE and ABYC specifications and provide precise steering control not achievable with hydraulic industry standard hoses. Types of Hydraulic Steering Systems Two-line manual systems: In these systems the helm pump moves the hydraulic cylinder directly. In use, a clockwise turn of the steering wheel will send fluid from the helm unit into the starboard hydraulic line. This fluid will be pumped into the cylinder and either extend or retract the cylinder rod. Incoming fluid pushes a piston which is pinned to an external rod. As the piston is moved the rod is either extended or retracted, and the boat turns. Outgoing fluid from the other end of the cylinder is returned to the helm via the port side line. Three-line manual systems Hynautic: Three-line systems are pressurized and contain a separate reservoir and pressure-relief valve. Common on work and pleasure vessels up to 70 feet. Helms are simpler since they do not contain the reservoir or relief valve. The fluid fill is at a remote reservoir, instead of the helm. They use soft refrigeration type copper tubing, instead of nylon hose. Power assist: For outboards 150hp and above and for twin and triple engine applications, bass boats, pontoon boats, power catamarans and inboard cruisers without engine-driven power assist. Uses an electronically-controlled on-demand hydraulic pump to give your boat the same easy steering you are accustomed to in your car. Power steering: Larger boats require a bigger system that can handle higher loads typically experienced at the rudder(s). Power steering systems include two distinct operating circuits: A “manually-operated” hydraulic system of a standard SeaStar helm pump and hydraulic cylinder (fitted with an integral servo cylinder and power steering valve), and A “power” steering system of either an engine-driven pump (conventional) or an electrically-operated power assist pump. The manual circuit provides the control portion of the steering system, and the power circuit provides the power to turn the rudders. See the diagram of the new Optimus 360 system, which is NMEA 2000 compatible and uses a joystick control.