Regarding the service life of metal hoses

Our metal hose used at the unloading stations is subjected to a pressure resistance test once a year, at 4 times the working pressure. As for its lifespan, I think it depends on factors such as the working environment, medium corrosion, temperature, and pressure; there isn’t a fixed standard for it

You can ask the manufacturer about this; it seems that no specific standard defines it

Reply to 1# alcity: We use metal hoses for the feed pipe of our centrifuge. We haven’t started using the centrifuge yet; we ran water through it a few times, and for some reason it started leaking

The metal hoses at the base of oil tanks generally have a service life of 5 years; they are prone to bursting over time! Caused an accident!

The lifespan of a metal flexible hose is the shortest period of operation or number of cycles during which it can maintain normal performance under working conditions. An elastic sealing system composed of metal hoses often operates under conditions of varying loads with a high number of cycles and significant displacements; therefore, it is important to determine the service life of these metal hoses. Since the functions of metal hoses vary, the requirements for their service life also differ. 　　　 (1) When metal hoses are used to compensate for positional deviations in piping systems caused by installation, their service life needs to last only a few uses. 　　　 (2) Metal hoses are used in thermostatic controllers with high switching frequencies, and their lifespan must reach 10,000 cycles to meet the usage requirements. 　　　 (3) When metal hoses are used as vacuum seals in vacuum switches, their lifespan must reach 30,000 cycles to ensure normal operation.

There are two basic load conditions for the fatigue life testing of metal hoses: working pressure load and cyclic displacement load. The working pressure load refers to the testing of the flexible metal hose under nominal pressure conditions, while the cyclic displacement load requires that the nominal displacement amount of the flexible metal hose be achieved. Cyclic displacement loading is easy to implement during testing, whereas working pressure loading tests present certain difficulties. This is because a liquid medium must be used during the test, and as the metal hose is compressed or stretched, its volume changes continuously. Due to the incompressibility of liquids, pressure changes significantly as volume changes, which prevents accurate testing results from being obtained. Therefore, a stable pressure system is necessary to maintain equilibrium and stability of the pressure inside and outside the bellows during the test, ensuring that pressure fluctuations do not exceed specified limits. To address this issue with the flexible metal hose, a pressure stabilization system was applied, as shown in Figure 1. During the test, first place the bellows on the high-pressure cylinder, allowing the upper clamp to make contact with one end of the bellows. The high-pressure cylinder is connected to a pressure stabilization system, which is used to maintain a constant pressure. In addition, the actuators, crossbeams, sensors, etc., are controlled by a separate control system, and during the test, the computer control system oversees and records the entire testing process until the bellows ruptures and leaks. By applying the aforementioned methods and testing apparatus, fatigue life tests under pressure and displacement conditions of 20 MPa and an axial displacement of 100 mm can be conducted accurately.

This post was last edited by alcity on 2011-8-13 09:18. Reply to 5# Yifekeshao: “The metal hoses at the base of oil tanks generally have a service life of 5 years; they are prone to bursting over time!” Caused an accident! ” It’s probably the rule of their own factory.

Where are flexible metal hoses used? Our high-quality metal hoses are used to connect the production water! Haha, so it’s hard to say about the lifespan! If it’s a stacker, it seems that the use of hoses is no longer allowed! Safety precautions

"The metal hoses at the base of oil tanks generally have a service life of 5 years; they are prone to bursting over time! Caused an accident! ” It doesn’t seem to be strictly regulated, but it’s still an issue worth paying attention to. Our liquid chemical storage tanks have been in use for 12 years now, and the metal hoses in front of the tanks have never been pressure-tested or replaced. We’re considering how to deal with this situation; does anyone here have any experience to share?

There is likely no specific time limit; the flexible metal hose should undergo a pressure resistance test once a year