Proper hose selection is critical to a safe hydraulic system. A simple rule of thumb for proper hose selection is the word “STAMPED”S Size
The first step in achieving a safe hydraulic system is selecting correct components that meet your needs. Compromises in components selection, either hose or couplings, may put you in danger, as well as affect the performance and life of your system.
S - Size: The inside diameter of the hose must be adequate to keep pressure loss to minimum and avoid damage to the hose due to heat generation created by excessive turbulence.
T - Temperature: The hose selected must be capable of withstanding the minimum and maximum temperature of the system. Do not expose hose to internal or external temperatures exceeding the recommended limits. An increase of 10°C above the maximum recommended temperature may reduce the hose life by half. Also, hose will crack if flexed at temperatures below the minimum recommended.
A - Application: Select the proper hose for the application. Determine where, or how, the assembly is to be used.
M - Material: Hose selection must assure compatibility of the hose tube, cover, reinforcement, couplings, o-rings, etc., with the fluid used. Many hoses are compatible with one type of fluid or another, but often times not all fluids.
P - Pressure: It is essential in the hose selection process to know the system pressure, including pressure spikes. Published working pressure must be equal to or, greater than the system pressure. Pressure spikes greater than the published working pressure will shorten hose life or lead to hose ruptures.
E - Ends: Connecting ends of coupling must be correctly identified.
D - Delivery: How much fluid must go through the hose? This will determine the size of hose that must be used. Under sizing a hose leads to increased pressure loss, while over sizing the hose adds unnecessary cost, weight and bulk.