Fox-VPS Servo Actuators offer a range of control and service manifolds for optimum test control and safety, including:

  • Integral Manifolds to suit all types of Servo and Proportional Valves
  • Hydraulic Safety Manifolds for active (structural) and re-active (systems) testing
  • Hydraulic Service Manifolds
  • Hydraulic Distribution Manifolds


FOX-VPS can offer manifolds to suit all types of Servo & Proportional Valves with either ISO 10372 or ISO4401 (CETOP) interfaces. Accumulators can be fitted to reduce pressure transients during cyclic duties, thus increasing the service life of the hydraulic system. Please discuss your requirement with FOX-VPS engineers to define the most suitable manifold system for your application.

Safety Manifolds:

As test specimens become more complex and sophisticated utilising the latest construction techniques and with operational requirements forever pushing design boundaries, inexorably they become more expensive. The Test Engineer’s worst nightmare is to damage the test article with an un-commanded event. FOX-VPS personnel have worked in close harmony with test engineers for many years to minimise this risk, identifying where cost effective, controllable and practical safety features are required.

FOX-VPS have developed a range of Hydraulic Safety Manifolds which provide high levels of test article security in a number of ways dependant upon the type of test performed. Manifolds can be directly mounted to their associated Test Actuator or ‘stacked’ together to form a single distribution point for a number of actuators.

Safety Features:

Safety components generally common to most types of Manifold include:

  • Load limiting pressure relief valves which may be independently adjusted in either direction between 2% and 100% of the actuator’s full load rating.
  • A solenoid operated loading valve to ‘arm’ the Manifold for use.

The safety circuitry is designed in house and, should standard circuits not suffice they can be readily customised to suit the user’s particular needs.

Actuator Manifolds

Active Testing:

In this type of operation the test actuator applies loads to a compliant structure, which absorbs and releases strain energy throughout the test. Active Test Manifolds are fitted with a series of logic elements and throttle valves that, in the event of an abort, isolate the Servo Valve and allow oil to discharge from the loading actuator in a controlled manner through a throttle valve. Check valves are utilised in asymmetric actuators to prevent cavitation should the actuator extend during unloading.

Re-active Testing:

In this instance the test actuator is utilised to apply loads to a power source, such as an aircraft actuator. The test article has no stored energy and must continue unimpeded in the event of an abort. Reactive Test Manifolds are fitted with a series of logic elements that, during an abort, isolate the Servo Valve and connect the actuator ports together, allowing the test article to move the loading actuator unimpeded.

Remotely Mounted, Stacked Manifolds:

Both types of manifold are available in a remote mounting style that can be connected together, as shown below, providing a compact unit with a single supply and return interface. Up to 6 manifolds can be mounted on a purpose built wheeled trolley, a series of which can connected to form a chain with a single connection to the hydraulic supply.

Associated Manifolds

Hydraulic Service Manifolds:

FOX-VPS has developed a range of Hydraulic Service Manifolds (HSM) to compliment the FOX-VPS hydraulic test actuator range and to facilitate control and distribution of the hydraulic supply. Fitted with a pressure control valve, 3 micron pressure filter and pressure & return hydraulic accumulators, a FOX-VPS HSM provides control, filtration, pressure ripple smoothing and flow augmentation of the pressurised oil supply to the actuator. The HSM isolates the main pressure source from the test actuator (or distribution manifold) and provides interlocked independent control of oil outlets. Main supply pressure is selectable OFF/LO/HI by two solenoid valves with smooth transitions between LO and HI pressures in either direction.

Hydraulic Distribution Manifolds:

FOX-VPS Hydraulic Distribution Manifolds (HDM) provide an interface between the HSM and individual hydraulic test actuators. Pilot, main and return lines are through drilled enabling a series of HDM to be connected together if desired. Each HDM actuator channel is fitted with an outlet isolating ball valve and a return line check valve. HDM are available as standard with 4, 6 & 8 outlets and are mounted on a sturdy steel frame complete with drip tray. Alternative channel quantities are available on request.

Hydraulic Valves:

FOX-VPS has many years experience in the design and manufacture of hydraulic valves for a wide range of applications and can provide bespoke solutions tailored to customer’s requirements.