Stainless fittings and machined parts for hydraulic steering gear and actuators

The steering system is one of the systems on a boat or ship that can least afford to fail. In hydraulic steering, the pump, cylinder and the lines between them, and on the mechanical side the rods, pins, bushings and rod ends, all operate under seawater, humidity and constant movement. The same goes for actuation assemblies such as passerelles, ship cranes, hatch covers and ramps. For these parts, stainless steel is often not an option but a requirement.

Scope

Hydraulic steering connections

• Steering cylinder port connections: fittings, adapters, elbows and tees
• Hose assemblies and tube line connections between the steering pump and cylinder
• Flexible hose connections and stainless steel ends that accommodate cylinder movement
• Check valve and ball valve connections on the line

Machined actuation components

• Rod ends, pivot pins and bushings
• Cylinder mounting ends and stainless steel parts at connection points
• Cylinder connection parts for passerelle, crane, hatch cover and ramp hydraulics
• Remanufacture of worn or broken stainless steel parts from samples

Machined parts are produced to a technical drawing or sample. For load-bearing and safety-critical parts, dimensions, material and tolerances are determined based on the system manufacturer's drawing or the shipyard's approval.

How is it done?

Identification

On the existing system, the thread standard of the cylinder ports, the hose diameter and length, and the path the hose follows during movement are determined. BSP, NPT, UNF/JIC and metric connections can be found together in the same system on boat and ship equipment, and imperial and metric sizes may appear side by side on steering systems of foreign origin. That is why threads are identified by measurement, not by guesswork.

Hose on a moving connection

For hoses that move with the cylinder, the length is set so that the hose is neither stretched nor bent below its bend radius at either end position of the rudder. The hose is never installed twisted, and points where it rubs against the hull structure or neighboring equipment are checked.

Machined parts

For parts such as pins, bushings and rod ends, fit tolerance, surface finish and material are evaluated together. Because stainless steel surfaces that rub against each other carry a risk of galling, the material of the mating part and the lubrication conditions are taken into account in the design. When manufacturing from a worn sample, the original dimension is established by comparing the amount of wear with the dimensions of the mating part.

Passerelle, crane and hatch cover hydraulics

On passerelle, ship crane, hatch cover and ramp systems, cylinders operate over a wide range of motion and out in the open. The pins and bushings at the cylinder mounting ends wear under both seawater and variable loads. If the hose connections on the same cylinder are also checked when these parts are renewed, the risk of a second shutdown shortly afterwards is reduced.

Quality control

• Check of thread standard and port fit against the mating part
• Diameter, fit and surface check on pins and bushings
• Crimp, length and orientation angle check on hose assemblies
• Pressure and leak-tightness verification depending on the application
• Parts labeled by installation position and packed separately

What to prepare for a request

• Make and model of the steering system or equipment
• Photos of the part, caliper measurements or a technical drawing
• Cylinder port threads, hose diameters and existing hose lengths
• Quantity and target date (drydocking or launch schedule)

Applications by sector

Boat builders and marinas; shipyards and ship repair companies; steering system manufacturers and service providers; passerelle manufacturers; ship crane manufacturers and crane maintenance providers; deck and actuation hydraulics on offshore support vessels; actuation connections on naval platforms in the defense industry.

Lead time

Fittings, adapters and hose ends from stock are typically prepared within 1-3 business days, and made-up hose assemblies within an average of 5-15 business days. Machined parts produced from samples or technical drawings are scheduled within an average of 10-20 business days after technical approval. If measurements are taken and samples sent early while the boat is on the hard or the ship is in dock, parts can be scheduled around the launch date.