When we design our hydraulic system project or replace the old system, an important question always comes to our mind, how do we make the proper hydraulic hose selection, to ensure safe application with reliable sense and prolong their service life? Many experts come down to the STAMPED solutions to resolve this issue, and they are right, but this time, I want to break down this question from our perspective.
Hydraulic hose pressure rating
Hydraulic hoses are obliged to convey pressurized hydraulic fluid between the hydraulic components, thus, hydraulic hoses must sustain certain pressure, and hydraulic hose selection should align with certain pressure ratings due to specific requirements.
Working pressure is the rated pressure that a hydraulic hose can endure, in working status, the hydraulic fluid pressure in the inner hose must be lower than the working pressure of the hose. Even momentary surfs pressure spike should be under working pressure, Don’t take adventures and ignore that, whatever kind breaks or damages the hydraulic hose maybe arouse a huge loss of a human being’s life and some treasure.
The safety factor is the ratio of bursting pressure and working pressure, which is a built-in parameter in the SAE J517 stipulation. In the hydraulic industry, a 4:1 ratio is considered a safety application, for instance, the working pressure of a hydraulic hose is 3,000PSI, and its bursting pressure is 12,000PSI.
The burst pressure test is destructive, put the testing hydraulic hose at the burst pressure test machine, and pressurized the media in the inner tube continuously until the hose explodes or leakage occurs in any part of the hydraulic assembly.
Pressure endurance is the mission of hydraulic hoses, when other factors are determined, hydraulic pressure rating is the primary element to consider, after all, security is first.
Impulse test results can reflect the lifespan of the hydraulic hose. Impulse cycles are sudden on-off pressures that cause stress to a hose, they are typically conducted at 133% of the working pressure rating, In SAE criteria, each type of hydraulic hose has stipulated circles, 200,000 is considered as the threshold for many hoses.
Size & demension
It is not difficult to understand that a suitable size matches a suitable application, just like your clothes match your figure, but the size involves three types, inner diameter, outer diameter, and length.
When flow capacity per min is determined, the flow viscosity tightly relates to the inner diameter, if the I.D. is too fine, much turbulence exists in the inner tube, decline the pressure power along the length, and conversely, the viscosity is sluggish, and hydraulic fluid can’t convey hydraulic power effectively. The flow capacity monogram and its formula can give you recommendations about the size of the inner diameter.
In case the inner diameter is determined, the outer diameter is generally in the range of a certain size, because SAE has set up a set of parameters for a specific hydraulic hose, only check them if adhering to your needs.
The length of the hydraulic hose is necessary to take more consideration, how to mount them on your machine has a set of norms, notice the bending radius, both too tight and too loose are not sensible.
The materials to manufacture hydraulic hoses are synthetic rubber, and the accepted temperature range is from -40°F to +212°F, nitrile rubber is generally used for extruding inner tubes, they keep in touch with hydraulic fluid and are compatible with the fluid. Neoprene rubber is used for the outer cover since it has good resistance to corrosion and abrasion from ambient environments. EPDM rubber is suitable for high-temperature use.
Teflon and Thermoplastics are also involved in some special occasions. PTFE hydraulic hoses are accommodated in high-temperature use and some scenarios that require chemical resistance. Thermoplastic hydraulic hoses have lightweight and tight bend radii. they often find their use on mobile vehicles with inner diameters less than 1″.
Hydraulic fittings are crimped on the two ends of the hydraulic hose to form a hydraulic assembly, so they can be embedded in the system with a solid connection.
It is worth mentioning that opting for the right size for the hydraulic fitting to match the hose, correctly crimping the ferrule at the end of the hose, and ensuring the connection port and thread to the hydraulic components are all considerations you have.
From the description above, I think it is not difficult for you to conduct a hydraulic hose selection, although there are dozens of types of hydraulic hoses, in my perspective, pressure rating, size, material, and hydraulic fittings are four essential factors for you to determine a hydraulic hose.
Sinopusle Group is manufacturing all kinds of hydraulic hoses to meet your requirement, we accept custom orders, and if you have some problems choosing a hydraulic hose, we can help you with expertise.
Don’t hesitate to contact us now.