Precision tubes for hydraulic lines
Tube sizes acc. to EN standard, ASTM standard, JIS standard.
Precision tubes are made using the cold drawing process. The rolled seamless tubes are used as the semi-finished product. Precision tubes are made from carbon and alloyed steel. Tubes are destined for hydraulic distribution systems and circles.
Tube dimensions for hydraulic lines,
Inside diameter ranges from 6 to 80 mm and wall thickness ranges from 1.0 to 12.5 mm. Precision steel tubes are delivered according to EN 10305-4, DIN 2391-1. More detailed overview of produced dimensions according to EN standards, according to ASTM standards and according to JIS standards.
The Steel grades for the hydraulic lines
Tubes are produced from the following steel. According to EN 10305-4: E215, E235, E355 and according to DIN 2391-2C: St35 and DIN 1630: St37.4, St44.4, St52.4. Steels are produced in an electric arc furnace and they are fully killed. Upon agreement it is possible to deliver other types of steel.
Allowable pressure for hydraulic lines
The highest allowable pressure for hydraulic lines in relationship to steel and tube testing is calculated according to DIN 2413.
Delivery condition and thermal treatment of the tubes for hydraulic lines
Tubes are delivered as cold drawn and normalized NBK according to DIN, +SR according to EN, . N according to ASTM. Coarseness of the outer and inner surface (starting with 15 mm of the inside diameter) is Ra <= 4 micrometers (0.004mm).
Length of the tubes for hydraulic lines
- manufactured length of the precision tubes is 6 meters (tolerances at the standard length is 0 + 50 mm and at the exact length is 0 + 10 mm)
- exact length is in the range of 3 000 - 9 000 mm.
Tolerances of the tubes for hydraulic and lines
Tolerances of the precision tubes meet the appropriate standards. MEILONG offers precision tubes with tighter tolerances, i.e. tolerances that are tighter compared with the standard values.
Straightness of the tubes for hydraulic lines
3 mm / m (1 : 1 000), overall straightness is 0,0015 % maximum of the total length of a tube.
Ends of the tubes
The ends of the tubes are smooth and enclosed with a plastic plugs.
Marking of the tubes
Each tube is marked by the InkJet system along the whole length according to standards or according to customer requirements. Tube bundles for hydraulic lines are marked by tags.
Surface protection of the tubes for hydraulic lines
The tubes are delivered as oiled, phosphated or electrolytically galvanized and chrome-coated.
Packaging of precision tubes for hydraulic lines
The tubes are delivered in bundles with either circular or hexagonal cross-section weighing maximum 2000 kilograms. The tubes are tied with a steel band. Upon agreement it is possible to protect the surface with paper lining or protect the ends of the bundle with PVC foil.
Testing of the tubes
The electromagnetic nondestructive testing of leak tightness is always performed according to EN 10246-1 or other corresponding standards. Selection of the tests is defined in EN 10305-1. On the top of it the NDT test and the flattening or drift expanding test is possible.
Certificates for the tubes
According to the following standards: EN 10 204 or DIN 50049
Specified testing 3.1.B or 3.1
Upon agreement - 3.1.C or 3.2
Standards and steel grades
| Standard | TDR | Steel Grade |
| ASTM | | |
| ASTM | A822/A450 | A822 |
| BS | | |
| BS | 7416 | 430LT |
| BS | 7416 | CFS 360 |
| BS | 7416 | CFS 430 |
| DIN | | |
| DIN | 2391-2C/2445-2 | St 35 |
| DIN | 1630/2445-2 | St 37.4 |
| DIN | 1630/2445-2 | St 44.4 |
| DIN | 1630/2445-2 | St 52.4 |
| EN | | |
| EN | 10305-4 | E215 |
| EN | 10305-4 | E235 |
| EN | 10305-4 | E355 |
| JIS | | |
| JIS | JOHS-102 | OST 1 |
| JIS | JOHS-102 | OST 2 |
| JIS | JOHS-102 | STPG370 |
| JIS | JOHS-102 | STS370 |
| NF A | | |
| NF A | 49-330 | TU 37B |
| NF A | 49-330 | TU 42B |
| NF A | 49-330 | TU 52B |
