Ost1 90050-72. Titanium alloy tubes. Technical requirements.
1. SORTMENT
1.1 Dimensions of BT1-00, BT1-0 and OT4-0 grade alloy tubes must meet the requirements
| Outer diameter, mm | Wall thickness, mm | mm | mm | mm | mm | mm mm |
|---|---|---|---|---|---|---|
| 1,0 | 1,5 | 2,0 | 2,5 | 3,0 | 3,5 | 4,0 |
Maximum length of measured titanium tubes, mm
| Outer diameter, mm | Wall thickness, mm | mm wall thickness mm | mm | mm | mm | mm mm |
|---|---|---|---|---|---|---|
| 6 | 4,0 | |||||
| 8 | 4,0 | |||||
| 10 | 4,0 | |||||
| 12 | 4,0 | |||||
| 14 | 4,0 | |||||
| 16 | 4,0 | |||||
| 18 | 4,0 | 4,0 | ||||
| 20 | 4,0 | 4,0 | ||||
| 22 | 4,0 | 4,0 | 4,0 | |||
| 24 | 4,0 | 4,0 | 4,0 | 4,0 | ||
| 25 | 4,0 | 4,0 | 4,0 | 4,0 | ||
| 26 | 4,0 | 4,0 | 4,0 | 4,0 | ||
| 27 | 4,0 | 4,0 | 4,0 | 4,0 | ||
| 28 | 4,0 | 4,0 | 4,0 | 4,0 | ||
| 30 | 4,0 | 4,0 | 4,0 | 4,0 | ||
| 32 | 4,0 | 4,0 | 4,0 | |||
| 35 | 4,0 | 4,0 | 4,0 | |||
| 38 | 4,0 | 4,0 | 4,0 | |||
| 40 | 4,0 | 4,0 | 4,0 | |||
| 42 | 4,0 | 4,0 | 4,0 | |||
| 45 | 4,0 | 4,0 | 4,0 | |||
| 46 | 4,0 | 4,0 | 4,0 | |||
| 48 | 4,0 | 4,0 | 4,0 | |||
| 50 | 4,0 | 4,0 | 3,5 | |||
| 52 | 4,0 | 3,5 | ||||
| 54 | 4,0 | 3,5 | ||||
| 56 | 4,0 | 3,5 | ||||
| 60 | 3,5 | 2,5 | ||||
| 62 | 3,5 | 2,5 |
a/ of off-gauge length from 0.5 m to the value specified in Table 1.
b/ Of measured length and multiples thereof within the unmeasured length.
Allowable deviation in measured length shall not exceed + 15 mm.
Pipes of multiple straight length are supplied with 5 mm allowance for each cut and with + 15 mm tolerance on the total bottom.
1.6 Pipe sizes, grade and accuracy of manufacturing are specified in the purchase order.
2. TECHNICAL REQUIREMENTS
2.1 Chemical composition of pipe material shall meet the requirements of OCT1 90013-71.
2.2 Tubes shall be supplied annealed and etched.
2.3 Pipes outer and inner surface shall be clean, without cracks, delaminations, pits, scale and grease residues, etch rash, rough scraping marks, deep cuts and other rough surface defects.
The presence of different surface tints, as well as cross-ring and spiral traces of technological processing is not a rejection feature.
2.4 There shall be no altered layer on the pipe surface.
2.5 Pipes shall be evenly trimmed and free of burrs.
2.6 Pipes shall not be out of the outer diameter and wall thickness tolerances, respectively.
2.7 Pipe curvature on any length / no less than 1 m/ shall not be greater than:
tubing of BT1-00, BT1-0 and OT4-0 grades with a diameter of up to 35 mm - 1 mm per 1 m;
tubing made of BT1-00, BT1-0 and OT4-0 alloys with the diameter exceeding 35 mm and tubing made of OT4-I and OT4 alloys of all dimensions - 2 mm per 1 m length.
Overall curvature shall not be more than product of the allowable curvature per 1 meter for the total pipe length in meters.
2.8 Mechanical properties of pipes in delivery condition shall meet the requirements
| Grade of alloy | Tensile strength, kgf/mm2 | d5 |
| VT1-00 | 30-45 | 20 |
| VT1-0 | 40-55 | 15 |
| OT4-0 | 50-65 | 15 |
| OT4-1 | 60-75 | 12 |
| OT4 | 70-85 | 10 |
2.9 Titanium tubes shall withstand hydraulic pressure test.
The value of allowable stress "P" during hydraulic pressure test is set:
for tubes of BT1-00, BT1-0 and OT4-0 alloy grades - 17 kGf/mm2;
22 kgf/mm2 for OT4-I and OT4 alloy grade tubing.
2.10. Pipes of BT1-00, BT1-0, OT4-0 and OT4-1 grades with diameter up to 40 mm must withstand upsetting test on mandrel with taper rate of 1:10 till increase of outer diameter by 10 %. Pipes made of OT4 grade alloy with a diameter of up to 40 mm shall withstand a handout test by an amount to be specified by agreement of the parties.
2.11. Pipes shall pass the flattening test to the distance between flattened surfaces as specified by agreement of the parties.
