Ost1 90065-72. Increased quality titanium alloy tubes. Technical requirements.
1. SORTMENT
1.1 Pipe dimensions and tolerances shall meet the following requirements.
Wall thickness and allowable deviations, mm
| Outer diameter, nn | Tolerance, mm | 0,5±0,07 | 0,75±0,08 | 1,0±1,0 | 1,5±0,15 | 2,0±0,2 |
|---|---|---|---|---|---|---|
| 8 | ±0,12 | Х | Х | Х | ||
| 10 | ±0,12 | Х | Х | Х | Х | |
| 12 | ±0,15 | Х | Х | Х | Х | Х |
| 14 | ±0,15 | Х | Х | Х | Х | Х |
| 16 | ±0,15 | Х | Х | Х | Х | Х |
| 18 | ±0,15 | Х | Х | Х | Х | Х |
| 20 | ±0,20 | Х | Х | Х | Х | |
| 22 | ±0,20 | Х | Х | Х | ||
| 24 | ±0,20 | Х | Х | Х | ||
| 25 | ±0,20 | Х | Х | Х | ||
| 26 | ±0,25 | Х | Х | Х | ||
| 27 | ±0,25 | Х | Х | Х | ||
| 28 | ±0,25 | Х | Х | Х | ||
| 30 | ±0,25 | Х | Х | Х |
1.2 Tubes are supplied in length:
a) off-gauge lengths from 0.5 m to 4 m;
b) regular and multiple lengths within the off-gauge length.
Allowable deviation at cut length shall not exceed + 10 mm.
Pipes of nominal length are supplied with 5 mm allowance for each cut, and with tolerance on the total bottom + 10 mm.
1.3 Pipe dimensions, alloy grade and manufacturing accuracy shall be specified in the 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 surfaces 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 Ovality and variation in pipe dimensions shall not exceed the outside diameter and wall thickness tolerances, respectively.
2.7 Piping curvature at any length (not less than 1 m) shall not exceed 1 mm per 1 lineal meter.
2.8 Mechanical properties of pipes in delivery condition shall meet the following requirements.
| Alloy grade | Tensile strength, kgf/mm2 | d5 |
|---|---|---|
| ВТ1-00 | 30-45 | 25 |
| VT1-0 | 40-55 | 20 |
| OT4-0 | 50-65 | 18 |
Note: d5 - Relative elongation at break %.
2.9 Titanium pipes shall withstand hydraulic pressure test.
Value of allowable stress "P" in hydraulic pressure test of pipes is set at 17 kgf/mm2.
2.10. Pipes shall withstand flattening test to the distance between flattened surfaces to 1/3 of the original diameter.
2.11. Pipes titanium shall withstand the crush test on a mandrel with taper of 1: 10 up to 10% increase in outside diameter.
* The page contains an extract from OST1 90065-72 "Increased quality titanium alloy tubes. Technical requirements".
