Fundamentals and hose selection
Technical reference and selection guides on fundamentals and hose selection.
15 guides
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What information is needed to select a hose?
Hose selection does not start with diameter and pressure alone. The fluid, temperature, application, dimensions, pressure/vacuum and end connections must be defined together. STAMPED is a reminder used to gather this in…
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How are inside diameter, outside diameter and overall length defined?
Inside diameter denotes the flow path, outside diameter the outer envelope, and overall length the assembly length between two defined references. These three dimensions cannot be used interchangeably. The cut length of…
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The difference between working, test and burst pressure
Working pressure refers to the service limit, test pressure to a defined test condition, and burst pressure to a separate strength test. The burst value is not a usable working pressure; no single universal ratio is ass…
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How are fluid and ambient temperature distinguished?
Fluid temperature is the condition the hose sees from the inside, and ambient temperature the condition it sees from the outside. Both are assessed in selection. Continuous operation, short-term peak, start-up and clean…
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Selection differences between suction and discharge applications
A discharge hose must be suitable for internal pressure, while a suction hose must be suitable for the external-internal pressure difference in the application. A high positive working pressure rating is not a guarantee…
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How to prepare a technical hose request form
A technical request form should make the unknowns in the application visible rather than ask for a product name. Fluid, temperature, pressure/vacuum, dimensions, movement and end connections are the core fields. Unknown…
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Guide to writing a hose assembly technical specification
A hose assembly specification defines the service conditions, the hose model or performance requirement, the A/B ends, overall length, orientations and acceptance documents in the same revision. The phrase 'hose with fi…
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Deriving a correct order definition from a sample hose
When preparing an order from a sample, visible dimensions must be separated from unknown service conditions. A sample is valuable for investigating product identity; however, on its own it does not show why it was selec…
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How to compare technical equivalence in quotations
Quotations are technically meaningful only if they are compared on the basis of the same service condition, the same assembly scope and the same acceptance terms. Placing a price per meter directly next to the price of …
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Questions to ask when an equivalent product is requested
In an equivalence assessment, the requirements to be met are fixed first, and then it is shown with which document the candidate product meets them. The same diameter, a similar appearance or the same standard family do…
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Why inch-to-millimeter conversion is not a nominal size match
One inch is exactly 25.4 millimeters. This length conversion is not an actual diameter match for a nominal hose size or a pipe thread. In an order, keep the numerical conversion separate from the product size definition.
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DN, dash and nominal hose sizes
DN, dash and inch expressions are not the same kind of dimension. DN is a nominal size designation; in many hose families, dash is used as a size code in sixteenths of an inch. However, the meaning of the code must be v…
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How to read the markings on a hose
The layline is the identification and property marking on the outer surface of the hose. It may include manufacturer, series, nominal size, pressure or standard information; the content varies by product family. A photo…
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Measurement references for hose length and end connections
A length order must give a start and end reference along with the number. Fitting ends, sealing surfaces, elbow axes and bare hose ends can be different references. Unless the supplier and customer use the same referenc…
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Pressure units and the gauge vs. absolute pressure distinction
bar, MPa and psi are pressure units; the terms gauge and absolute indicate the reference of the pressure. Unit conversion does not change the reference. Especially in vacuum, gas and steam assessments, it must be clear …
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