Pressure and Diameter of High-Pressure Rubber Hoses: The Conversion Relationship That Must Be Unders

There's an easily overlooked rule in selecting high-pressure rubber hoses: the larger the diameter, the lower the pressure-bearing capacity. Hoses of the same model but different diameters can have significantly different pressure ratings. Understanding this rule is key to avoiding selection errors.


I. The Negative Correlation Between Pressure and Pipe Diameter

Taking large marine high-pressure oil hoses as an example, their technical performance indicators clearly reflect this rule: product code 2SP-152-8 has an inner diameter of 152mm and a working pressure of 8MPa; while product code 4SP-304-16 has an inner diameter of 304mm and a working pressure of 16MPa. Doubling the pipe diameter changes the pressure-bearing capacity.

For products of the same model but different specifications, the minimum burst pressure is usually three times the working pressure. When selecting large-diameter pipelines, the pressure parameters of smaller diameters cannot be used as a reference; the actual working pressure value of the corresponding specification must be checked.

II. Flow Rate Basis for Inner Diameter Selection

The inner diameter of the hose must be appropriate. A diameter that is too small will increase the flow velocity of the medium inside the hose, causing the system to overheat, reduce efficiency, and generate excessive pressure drop, affecting system function. A diameter that is too large will increase procurement costs and affect normal system operation. The required inner diameter should be calculated based on the system flow rate and recommended flow velocity (usually 6-10 m/s).

When the hose is fixed with clamps or passes through a steel plate, attention should also be paid to the outer diameter of the hose to ensure sufficient installation space.

III. Pressure Rating Selection Strategy

Each high-pressure hose has a maximum working pressure, and the burst pressure is four times the maximum working pressure. Higher pressure ratings result in higher prices; therefore, the maximum working pressure should be selected based on the actual system pressure to ensure normal operation and save procurement costs. If the system experiences frequent impact pressures, products with a longer pulse life should be selected, and the maximum working pressure should be appropriately increased.

IV. Selection Operation Suggestions

Step 1: Calculate the required inner diameter based on the system flow rate. Step 2: Find the corresponding working pressure for that inner diameter. Step 3: Confirm that the working pressure is not less than 1.25 times the system's maximum pressure. Step 4: Confirm that the installation space meets the requirements for the outer diameter and bending radius of this specification.

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