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Hose Failure Analysis
Source: | Author:LISHI | Publish time: 2017-10-20 | 565 Views | Share:
Hose failures can be caused by conditions such as excessive pressures, fluid incompatibility, extreme temperatures, and many more. Selection of the proper hose for the application is essential to the proper operation and safe use of the hose and related equipment. Inadequate attention to selection of hose for application can result in serious bodily injury or property damage.

1

Problem: Hose has burst. Rusted wire, torn and rotted fibers are present. This was caused by abrasion damage. Exposure to elements will accelerate the deterioration.

Solution: Route the hose so it does not rub against other objects while under pressure. Suggest using clamps and spring guards to protect.

2 

Problem: Hose has burst on outside bend of hose. This hose has been bent past minimum bend radius. It has also taken a set in a bent position due to a kink in the inner tube or reinforcement.

Solution: Check minimum bend radius for hose. Utilize bend tube elbows if possible.
3 

Problem: Excessive heat. Hose cover or inner tube is brittle and cracked and is not flexible at room temperature.

Solution: Use hose with higher temperature rating or protect from heat with shields. Examine entire system for potential heat source. For example: undersized lines, excessively long lines, too many bends and/or fittings, reservoir low on oil.


Problem: Incompatible fluid. Portions of the inner tube are swollen and/or washed out. Cover may also be swollen.

Solution: Make sure hose used is compatible with fluid being used. Refer to chemical compatibility chart.


5

Problem: Hose cover blistered and pulling away from carcass. Gas has effused through the tube and become trapped under the cover.

Solution: Use perforated, pin-pricked or fiber cover hose.
6

Problem: End fitting blown off. Improper assembly procedures, incorrect hose fitting series, mixing different manufacturers’ components.

Solution: Refer to hose assembly procedures and Hose Fitting and Tool Selector Chart in the catalog. NEVER intermix components.
7

Problem: Hose has burst cleanly with no random wire breakage and cover abrasion. This condition is caused by excessive pressure.

Solution: Use hose with higher pressure rating. Check pressure relief for damage or improper setting.

8

Problem: Hose has burst. Hose is permanently twisted and kinked. Many broken wires in failure area.

Solution: Hose twisting can reduce hose life 90%. Tighten ends properly. Reroute hose to eliminate twist. Route hose to flex in only one plane. Use hose layline for a guide.

9

Problem: End fitting blown off. This condition has been caused by improper skiving. Any remaining cover on hose in the crimping area will prohibit proper end retention.

Solution: Make sure hose is properly skived. Refer hose skiving instructions.

10

Problem: Hose fitting appears to have been pinched on one side.

Solution: This is an early sign of collet wear. Replace collet.