Hydraulic hoses are widely used in construction machines, forestry machines, and mining machines all over the world, they contribute to the production activities of human beings, but do you consider how people living in extremely cold areas develop their construction and production, how can these machines run smoothly in the low temperature, how the hydraulic hoses on a special machine work well in the snowy and icy environment. thus, a hydraulic hose test for cold flexibility is necessary for these applications.
How can cold affect hydraulic hoses?
In SAE 100R and DIN EN series standards, the inner tube and outer cover are mostly made of synthetic rubber, synthetic rubber as a polymer can change its property when temperature decreases down to minus dozens of degrees, the measure indicator of polymer elastomer from high elastic to a glassy state is glass transition temperature which is called Tg, when ambient temperature decrease below the Tg, the synthetic rubber will become stiff, hard and brittle and loses its flexibility, and conversely, synthetic rubber can keep flexible in relatively high temperature.
In deep research, the long molecular chain of the rubber can rotate and vibrate when the temperature is above the Tg, however it will be limited in its original location when below Tg, hence, the rubber losses flexibility when the temperature is below Tg.
Develop an exclusive rubber recipe to overcome the harsh environments
Industry-standard hydraulic hoses are made to withstand a temperature range from -40°F to 212°F. When in freezing applications (-40°F to -70°F), we should opt for a low-temperature hydraulic hose. Low-temperature hoses are designed to support hydraulic hoses facing extremely cold environments, such as North European countries, Russia, Denmark, Fenland, Norway, and Canada in winter.
So, special prescriptions are developed to meet these needs in our lab, and the sequent tests after production ensures quality and smooth usage in extremely cold scenarios.
Hydraulic hose test for cold flexibility
The hydraulic hose test for cold flexibility simulates the real-site application, hydraulic hoses are frozen at -70°F in the refrigerator for 24 hours, and take them out, bend, and observe if there are cracks on the surface, and if they pass the visible inspection, and proceed the burst pressure test. If the pressure test result meets the client’s requirements or the stipulation of the standard. and then the products will make it.
In summary, the hydraulic hose test for cold flexibility is conducted at a low temperature (-70°F), visible inspection and burst pressure test are the two test indicators to determine if it is feasible.
How to protect your hydraulic hoses in freezing temperature
The special design of the hydraulic hose for freezing usage is not enough, we must take some measures to reduce the possibility of damage and prolong their lifespan in harsh conditions. Some tips are given below.
- opt for the right hydraulic oil to match the cold applications, the viscosity of the oil will increase when the temperature decreases, choose hydraulic fluids with a low viscosity index, the higher the viscosity index, the higher the resistance to change in viscosity.
- Protect your hydraulic hoses with a protective wrap or sleeve, keeping ice and snow away from your hoses and other hydraulic components.
- When your machine is off work, tear down the hydraulic hoses from the equipment, drain the hydraulic fluid, and store them indoors in a clean and dry area.
- When the machine began to work next time, take some time to warm up beforehand.
- Notice some rubber accessories like O-Ring, when tearing down or fixing the hydraulic hoses, if the O-ring has cracks, change them in time.
The two authoritative standards for hydraulic hoses, the SAE (Society of America Engineer) 100R series, and the EN(Europen Norm) series stipulated the temperature requirement for only common use, but in extremely cold temperatures, we should develop special hydraulic hoses to meet the requirements, hydraulic hose test for cold flexibility is must-do to ensure its quality.
In addition, taking some measures to protect the hose in cold conditions is an important supplement to safeguard your hydraulic hoses and prolong their lifespan.
Sinopulse Group is a professional hydraulic manufacturer in China, we have made hydraulic hoses and other rubber hoses for many years, and we can make hydraulic hoses as you required, the instance this article stated above is a good example, if you have some questions about that, don’t hesitate to contact us.