Harken’s integral hydraulic backstay adjuster provides the power to optimize sail shape quickly. The cylinder features a built-in, double-acting pump that delivers oil when the handle is both pushed and pulled. This moves oil through the system twice as fast as single-acting pumps on other integrals.
Assemblies include a hardcoat-anodized aluminum cylinder and pump, valve, gauge, and stainless pump handle with three attachment options: pin installs handle permanently; O-ring secures handle in socket, but is not permanent; nonlocking handle installs without O-ring and roll pin. All pins and plugs are stainless steel. Cylinders include a clevis on both ends. Standard eye-jaw toggles fit all Harken cylinders.
The pressure-release knob turns clockwise to close and pump, counterclockwise to release. When closing the pump, the knob cannot be over-tightened by hand, preventing damage to the valve. Release speed depends on how far open the knob is turned. Pressure relief is factory set to prevent crew from over-tensioning the backstay.
An analog gauge with pressure increments reading 0 - 5 (0 - 5000 psi) is prominently mounted at the top of the cylinder. The gauge adjusts to four positions for easy viewing from the cockpit.
Harken integral backstay adjusters come in four sizes to fit boats with 5 - 10 mm (7/32 - 3/8") wire—approximately 9 - 18 m (30 - 60').