A dual-source hose proof test stand requires a control architecture that manages two pressure sources with different flow and pressure characteristics, a safety interlock chain, and automated test sequence management. Here is the approach.
The dual-source architecture has two distinct operating phases. Phase 1 (fill and low-pressure ramp): the Rexroth electric gear pump runs with a throttle valve controlling ramp rate, filling the hose volume and raising pressure to the switchover point (typically 50–100 bar). Phase 2 (high-pressure ramp and hold): the Rexroth pump closes, the Haskel air supply valve opens, and compressed air metered through a precision regulator drives the Haskel to raise pressure to test pressure. The switchover is managed by the PLC based on pressure feedback from the system transducer.
The safety interlock chain implements a permit-to-pressurise logic. Before the fill phase can begin, all of these must be true: hood closure switch confirmed closed, hood latch switch confirmed engaged, no active emergency stop, pressure transducer reading ambient (no residual pressure from previous test), and operator start confirmation via two-hand start push buttons. Any of these becoming false during a test triggers immediate stop.
The test sequence for a proof pressure test is: fill (Phase 1 pump runs to switchover), ramp (Phase 2 Haskel raises to proof pressure at defined rate), hold (hold phase timer starts, pressure band monitored ±5 bar, any exceedance outside band triggers hold-fail), release (controlled vent through needle valve to ambient), disconnect permissive (only available after pressure confirmed at ambient). The PLC logs timestamped pressure readings throughout and generates a pass/fail record at test completion.
The elongation measurement uses a laser distance sensor measuring the gap between a reference plate fixed to the test bench and a target plate attached to the floating end fitting of the hose. As the hose elongates under pressure, the target plate moves and the laser reading changes. This measurement is captured at hold pressure and compared against specification limits for the hose type under test.
The Neometrix Hydraulic Hose/Tube Proof Test Stand implements this dual-source sequencing with the safety interlock chain and automatic test record generation.
→ https://neometrixgroup.com/products/hydraulic-hose-proof-test-stand
Top comments (0)