A hydraulic hose is designed and used to transport hydraulic fluid to or between hydraulic parts, e.g. valves, tools and actuators. Hydraulic hose is normally reinforced using many layers since it is used/operated at high pressure.
Therefore proper pressure testing is required to be done before a hydraulic system hose is fitted into machine and used, as it can explode when subjected to high pressure and may result in to a very serious accident. A series of tests are usually done to establish the strength and weakness of the hydraulic and other type of hoses. Below is some info for general knowledge purposes only related to pressure testing of hoses:
The Burst Pressure test is a destructive type test method carried out on smaller lengths of hoses, normally usually between lengths of 18 to 36 inches. The test hose is destroyed during the course of such testing. This test defines how much pressure the hydraulic hose can withstands prior to its bursting.
This test is carried out by subjecting the hydraulic hose to high pressure till it bursts. The burst pressure is established during this process. This is the actual/real pressure at which the bursting of hose occurs.
The proof pressure test of hose is normally used on a hose for a certain length of time. The new hydraulic system hose normally has a proof pressure which is fifty (50) percent of the minimum burst pressure. However, the fire hose having woven jacket has a proof pressure which is 67% of the specified burst pressure.
The hydrostatic testing done on the hydraulic system hose being tested should not be more that of the proof pressures stated above. This need to be specifically monitored on fire hoses which are still in service. Applying the hose to the pressures higher than the one specified can result in weakening and deterioration of hose.
Hoses’ testing of hoses is done basically for making different lot of assembly. The first step of hose pressure testing: Prior to hose pressure testing, the hose to be visually inspected for external conditions &crimping dimensions of ferrule.
After visual inspection of Hoses to be pressure tested, the second step will be to prepare and connect the hose in pressure testing rig/machine for pressure testing. After connecting line for Testing, primary feeding of water is required for pressure testing & that will be done up to the time the assembly should become completely Air Free.
At the start of pressure testing of hose, the pressure will be increased gradually & every hold should be returned back to zero pressure before raising pressure in line. Once above preparatory steps are taken twice & thrice, pressure can be created & hold for 30 or 60 second, as per requirement of customer and/or hose pressure testing procedure.
For 30 Second pressure should be 2 Time of working Pressure & 60 Second Pressure should be 1.5 time of working Pressure. After testing Assembly should be clean with Air Pressure. After Testing Assembly should be plugged at both Ends. Tag should be provided on each assembly after Testing with Date & Reference. If the Hose Assembly need to store for longer time, please keep in PVC covered& sealed for dust & air free.
Always put tag on cover for customer order Reference, Date & Quantity and Length.