Nominal Reference Working Pressures for Steel Hydraulic Tubing
This SAE Information Report is intended to provide design guidance in the selection of steel tubing and related tube fittings for general hydraulic system applications. The information presented herein is based on tubing products which conform to SAE and ISO standards listed in the reference section.
This SAE Information Report has been revised as part of the SAE five year review process and to bring this document into line with global standardization. The Barlow Formula, The Boardman Formula and The Lame Formula were placed in Appendix A for a period of five years during the previous publication of this revised document. After the five year period this information was to be removed from this information report. However, the hydraulic user community is not yet comfortable with removing these formulas. Therefore, these formulas will remain for another five year period at which time removal will be discussed further. In this revision ISO 10763 is the only formula that has been used to calculate the working pressures presented in the body of the document.
Tables 1 through 5 have been reallocated to comply with SAE guidelines to present our FCCTC tube standards in metric sizes.
Tables 6 through 10 have been allocated and updated to show compliance with all appropriate currently available SAE carbon steel and alloy steel tube standards in inch sizes.
The eventuality of the USA converting to hard metric tube sizes is in the hands of the OEM’s. Until this conversion happens, the hard metric tube sizes, which have very low usage in the USA, will remain difficult to source, more expensive and therefore, will probably remain in the future, rather than the present, of which we as standards writers, continue to contemplate. Perhaps one day the inch size tubing and components will be of a minority of usage and the hard metric will be the majority of usage.
Please note the changes as follows:
Added Rationale and statement concerning metric size tubing and inch size tubing
Updated Applicable Publications and Related Publications
In 1.5 added reference information to SAE J2658 and SAE J2593, removed reference to SAE J343, this SAE hose standard is not applicable to hydraulic tube assemblies.
In 3. added current standards take precedence statement
In 4. added reallocated Tables 1 through 5 for the various materials of metric tube sizes and added Tables 5 through 10 for the various materials of inch size tubing.
In Tables 8 and 9 removed unneeded nominal reference working pressures that are unreasonably high.
Updated all pressures rounded using “rule of seven”.
Removed bold line and note concerning SAE J533 Flaring from all tables because this information has been proven inaccurate, inconsistent and no particular value to the tube fabrication manufacturers.
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