Ost1 90050-72. Tubes from titanium alloys. Technical requirements.
1.1. The pipe sizes of the alloys BT1−00, BT1−0 and OT4−0 must meet the requirements of
|External diameter, mm||Wall thickness, mm||mm||mm||mm||mm||mm|
|The maximum length titanium tubes, mm|
a/ random lengths from 0.5 m up to the value specified in table. 1
b/ measuring the length and multiple within random length.
The tolerance for the measured length should not be more than + 15 mm.
Multiple pipe lengths are supplied with an allowance for each cut to 5 mm and with a maximum deviation of for the total dyno + 15 mm.
1.6. The pipe sizes, grade and precision manufacturing are stipulated in the order.
2. TECHNICAL REQUIREMENTS
2.1. The chemical composition of the pipe material shall meet the requirements of OCT1 90013−71.
2.2. Pipes are supplied in the annealed condition with corroded surface.
2.3. The outer and inner surface of the pipe must be clean, without cracks, delaminations, cavities, remnants of metal filings and grease, pickling rash, coarse traces of cleaning, deep scratches and other serious surface defects.
The various shades of the surface and cross-circular and spiral traces of processing, a symptom of rejection is not.
2.4. On the surface of the tubes should not be alteromonas layer.
2.5. The pipes must be trimmed evenly and must not have burrs.
2.6. Ovality and raznoshennoy pipes should not display their sizes for maximum deviations, respectively from the outside diameter and wall thickness.
2.7. The pipe curvature of the land is a source of any length /of at least 1 m should not be more than:
pipes made of alloys VT1−00, VT1−0 and OT4−0 with a diameter of 35 mm — 1 mm-1 TDG. m;
pipes made of alloys VT1−00, VT1−0 and OT4−0 with a diameter of over 35 mm and pipes of alloys OT4 and OT4 all sizes — 2 mm per 1 running. M.
The total curvature should not be more than the works permitted by the curvature of 1 m for the total length of the pipe in meters.
2.8. Mechanical properties of tubes in the delivery condition must meet the requirements of
|Grade||Rupture strength, kgf/mm2||d5|
2.9. Titanium tubes shall withstand a test hydraulic pressure.
The value of permissible voltage «R» when testing tubes hydraulic pressure is established:
for pipes made of alloys VT1−00, VT1−0 and OT4−0 — 17 kgf/mm2;
for pipes made of alloys OT4 and OT4 — 22 kgf/mm2.
2.10. Pipes made of alloys VT1−00, VT1−0, OT4−0 and OT4−1 with a diameter of 40 mm must withstand the test of the distribution on the mandrel with a taper of 1: 10 to increase the outer diameter by 10%. Pipe grade alloy OT4 with a diameter of 40 mm must withstand the test of the distribution by an amount which is established by agreement of the parties.
2.11. Pipe shall withstand flattening tests; to the distance between slowianski surfaces established by agreement of the parties.