1-SIZE

Vereks uses a system of measurement called Dash Numbers to indicate hose and fitting size. The dash number, or dash size, is the measure of a hose’s Inner Diameter (I.D.) in sixteenths of an inch. (The exception to this is SAE 100R5 hose. See the chart below for complete details.) This measuring system of the inside diameter of the hose is universally used by the fluid power industry today. Don’t know the hose size? Check the layline. If the original printing has worn off, the original hose must be cut and the inside diameter measured. Be sure to measure the overall assembly length and fitting orientation.

2- TEMPERATURE

When specifying a hose, two temperatures must be identified. One is the ambient temperature, which is the temperature surrounding the hose during use. The other is the media temperature, which refers to the temperature of the substance being conveyed through the hose.

Extreme ambient temperatures can negatively affect the hose cover and reinforcement materials, potentially reducing its service life. Media temperature can have an even greater impact on hose longevity. For instance, rubber loses flexibility when exposed to high temperatures for extended periods, which may lead to performance degradation.

3- APPLICATION

Before selecting a hose, it is important to consider how the hose assembly will be used. Answering the following questions may help:

• What type of equipment is involved?
• What are the environmental factors?
• Are mechanical loads applied to the assembly?
• Will the routing be confined?
• What about hose fittings – permanent or field-attachable?
• Will the assembly be subjected to abrasion?

Some applications require specific hoses. For instance, when hoses encounter rubbing or abrasive surfaces, our abrasion-resistant hoses with Tough and Super Tough covers are ideal. In tight spaces, the bend radius becomes a critical factor. Vereks offers a complete range of hoses designed for one-half SAE bend radius at full SAE-rated pressures. Our flexible hoses with smaller outer diameters allow for faster, easier routing in confined spaces, reducing hose length and inventory needs.

Industry standards establish specific requirements for construction type, size, tolerances, burst pressure, and impulse cycles. Vereks hydraulic hoses meet or exceed standards such as:

• SAE (Society of Automotive Engineers)
• EN (European Norm)
• DIN (Deutsches Institut für Normung)
• ISO (International Organization for Standardization)

4- MEDIA

What will the hose convey? Some applications require specialized oils or chemicals, making it essential to ensure that the hose you select is compatible with the medium being conveyed. Compatibility must extend to all components, including the inner tube, cover, hose fittings, and o-rings.

Refer to the Chemical Resistance Chart in Section E to choose the appropriate hose assembly components for your system. This chart provides chemical resistance ratings for a wide range of fluids, helping you select a hose that ensures safe and reliable performance.

5- PRESSURE

When considering hose pressure, it is crucial to account for both the system’s working pressure and any surge or spike pressures. The selected hose must have a published maximum working pressure that meets or exceeds the system’s maximum pressure.

Surge or peak transient pressures must remain below the hose's published maximum working pressure. Using a hose beyond its rated capacity can lead to failure, even if burst pressure ratings exceed the working pressure.

All Vereks hydraulic hoses meet industry standards for burst pressure and maintain a 4:1 design factor unless otherwise specified. However, burst pressure ratings are intended only for manufacturing tests and not for operational use. For this reason, burst pressure values have been removed from the hose charts in our catalog to emphasize safe usage within the recommended working pressure limits.