Materials and electrical properties
Technical reference and selection guides on materials and electrical properties.
15 guides
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How should NBR, EPDM and SBR be compared?
NBR, EPDM and SBR are different elastomer families. NBR may be investigated for oil contact, EPDM for outdoor exposure and certain water applications, and SBR for general mechanical and abrasion requirements; however, t…
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FKM, IIR and CR material families
FKM, IIR and CR denote different elastomer families; they cannot be used as if they were a single 'special rubber' class. Selection must be based on permeation, weathering, deformation and actual compound data in additi…
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Selection questions for UHMWPE and XLPE inner tubes
UHMWPE and XLPE are related to polyethylene but are different structural designations. UHMWPE refers to ultra-high molecular weight and XLPE to a cross-linked structure; no common pressure, temperature or chemical compa…
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Why a material name alone is not compatibility approval
The general chemical resistance of a material is not approval for the use of all hoses or fittings that contain that material. Compatibility is verified together with the actual product, fluid mixture, temperature, conc…
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Seal material, hardness and compound designation
Seal hardness and seal material are not the same information. Different hardnesses and formulations within the same elastomer family can behave differently; the correct seal is selected together with the connection geom…
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How does the stainless steel grade affect fitting selection?
Stainless steel is a family of materials; 304, 316 and other grades do not behave the same in every environment. Fluid, chlorides, temperature, stress and connection geometry are evaluated together; the word 'stainless'…
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Surface coatings on carbon steel fittings
On a coated carbon steel fitting, the coating is part of the resistance to the external environment; it does not replace the base material or the connection geometry. The coating type and test conditions must be evaluat…
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Fluid compatibility of brass fittings
When selecting a brass fitting, not only machinability or price but also the alloy, fluid, temperature and the documentation requirements of the application are evaluated. The name 'brass' is not a blanket declaration o…
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Corrosion when dissimilar metals are used together
Galvanic corrosion is a corrosion mechanism that can occur between dissimilar metals in electrical contact in a suitable electrolyte. Knowing only the names of the two metals is not enough to decide definitively whether…
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Protecting connections in salty and humid environments
In salty and humid environments, compatibility with the internal fluid is not sufficient for hose connections. External corrosion, moisture accumulation in crevices, dissimilar metal contacts and areas hidden under prot…
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Conductive, antistatic and insulating hoses: the differences
The terms conductive, antistatic and insulating do not mean the same thing. It should be stated which electrical property is defined by which test method and product standard; a single resistance range should not be ass…
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What does end-to-end electrical continuity mean?
End-to-end electrical continuity is evaluated between defined connection points on the completed hose assembly. Information given about the hose body or the metal reinforcement does not replace the measurement result fo…
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Is a metal helix proof of grounding?
A metal helix or braid is not in itself a verified grounding connection. How the metal contacts the ends, the continuity path and the application criteria must be clearly defined and measured; visible wire is not suffic…
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What information does an electrical resistance measurement record need?
An electrical resistance measurement record should contain the assembly identification, measurement points, method, instrument, conditions, result and acceptance source. An ohm value or a 'passed' statement alone is not…
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Gathering information for hose selection in explosive atmospheres
Hose selection for an explosive atmosphere is not completed simply by asking for an antistatic product. The gas or dust hazard of the area, process conditions, electrical requirements, hot surfaces and the use of the en…
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