Testing under pressure: recognising the dangers of hydraulics

The dangers that come with fluids under high pressures are well known.

The risk of workplaces injuries and recent fatalities in longwall scenarios related to contact with fluid under high pressure has only highlighted the dangers.

High pressure fluids or oil in hydraulic systems can be lethal if a fluid line connection point is opened or a hose failure occurs.

Unlike electrical energy and testing procedures, there has never previously been a non invasive pressure detection device that could test whether a hose, tube or pipe is under unreasonable pressure.

In a project funded by the Australian Coal Association Research Program (ACARP), Custom Fluidpower has developed a handheld non invasive fluid detection device.

Started in 2007, the company has finally created a working prototype.

“The principal use of the Portable Detection Device for Pressure in Hydraulic Hoses (PDD) is to inform an operator using the device on a hydraulic hose if there is high pressure or low pressure in the hose,” Custom Fluidpower engineer Liviu Schintee said

The device operates by applying a safe level of deformation to a hydraulic hose with a clamping device and measuring the deformation of this hose.

It then compares this deformation with data stored in its memory and issues a low pressure, high pressure or re-test notification

“This information is critical in performing isolation procedures in hydraulic circuits where is not possible to connect a pressure detecting device to measure the pressure in contact with the medium or hydraulic oil” he said.

In a complex hydraulic circuit with long lines not all the lines are provided with test points to allow pressure measurement.

“Potential application of this device is in performing the isolation procedure before servicing hydraulic hoses,” Custom Fluidpower sales sirector Neil Martin said

“Some hydraulic installations have stored hydraulic energy even if the installation is stopped.

“Disconnecting a hose under pressure can provoke injury by fluid injection. This hazard can generate a risk that cannot always be eliminated”.

Martin explained that by using the PDD, an operator can substitute the hazard of disconnecting a hose under high pressure with the risk of disconnecting the hose under low pressure.

This risk is more manageable and the risk of personal injury is lower” he said.

A second potential application is in identifying hoses under pressure in installations with long hose lines where the hoses are bundled and connected to different actuators or services.

This procedure will enable the technician to identify high pressure in hoses without unnecessary downtimes.

However, the PDD is not a substitute for existing safe work practices.