All Webtec hydraulic testers and the CTR series of Webtec turbine flow meters feature Webtec’s unique loading valve with built-in Interpass® safety protection and operate if maximum pressure is exceeded.
What Is Interpass®?
Interpass® is Webtec’s engineered safety burst disc system. It protects the hydraulic tester and load valve from damage if the system pressure exceeds the designated pressure limit for the tester. For example, this could happen if the operator accidently turns the load valve too far and excessively restricts the flow, thereby increasing the pressure beyond the acceptable level. Alternatively, if the load valve is partly closed and the operator accidently increases the motor or pump speed and the resulting increase in flow passing through the load valve could make the pressure spike beyond the acceptable level.
How Interpass® Works
The system operates much like a fuse in an electrical circuit. Since all Webtec turbine flow meters are bi-directional, most load-valves can also be used in both directions and typically contain two burst discs, calibrated to the tester’s maximum operating pressure, commonly 420 or 480 bar (6000 or 7000 psi), with other options available. When the pressure exceeds the rated pressure of the calibrated burst disc, the disc ruptures and allows oil to bypass the load valve at low pressure. Unlike traditional relief methods, Interpass® is designed so that the oil always stays inside the hydraulic circuit, reducing the chance of environmental contamination. Spare burst discs are supplied with every load valve, they are simple to change and spare packs of burst discs can be purchased from all Webtec distributors.