1. SORTMENT

1.1 Dimensions of small seamless pipes made of 1M and BT1-00 alloys and allowable deviations (in mm) shall be as specified below.

Outer diameter, mm	Tolerance for diameter, mm	Wall thickness of standard accuracy, mm	Wall thickness of precision, mm	Thickness tolerance	Length, mm
3,0	±0,05	±0,03	0,5	±0,05	measuring 2300+200
4,0	+0,08 -0,02	+0,04 -0,02	0,4	±0,05	not shorter than 1200

1.2 No more than 15 % (by weight) of the pipe length shall be shorter than 0.5 m.
1.3 Curvature of pipe shall not exceed 3 mm for pipes of normal accuracy and 5 mm for pipes of normal accuracy at any 1 m length.
1.4 Pipe ovality and wall thickness tolerances shall be within specified outside diameter and wall thickness tolerances.

2. TECHNICAL REQUIREMENTS

2.1 Titanium tubes are made of 1M and BT1-00 alloys, the chemical composition of which must correspond to billet specifications. The chemical composition of the alloy is accepted according to the certificate of the supplier of tubular billet.
2.2 Pipes shall be supplied heat-treated and etched.
2.3 No alphiated layer shall be present on pipe surface.
2.4 Pipes outer and inner surfaces shall be clean, bright and free of cracks, films, deep grooves and deep bruises.
2.5 Mechanical properties of pipe at room temperature in delivery condition shall conform to the following standards.

Grade of alloy	Tensile strength σB, kgf/mm2	Relative elongation δ5, %, no less
1М ВТ1-00	30-50	30

2.6 Each pipe is subjected to tightness test by injecting dry air into it under pressure of 3-5 atm. At that, the pipe shall be plugged at one end and immersed in water. No air leakage is allowed during the tests.
2.7 Pipes as delivered shall be subjected to technological test by winding 3-5 coils on a mandrel with a diameter not exceeding 1.3 of the pipe outer diameter. Absence of cracks visible to the naked eye is a sign of suitability.
2.8. Pipe ends shall be cut at right angles. Notching of pipes with file followed by bending is allowed.