RU98109782A - PIPE FROM HIGH-CARBON METAL WITH INTERNAL PLASTIC SHELL - Google Patents

Claims (1)

1. The pipe is made of high-carbon metal with an inner plastic sheath, containing protective sleeves located at the ends of the pipe and fastened with it, characterized in that the protective sleeves are made of metal with a carbon content of 0.07 - 0.14%, the ends of which protrude beyond the ends of the pipe a length greater than the thickness of the pipe wall and connected to the pipe ends by an integral mechanical connection and a weld. 2. The pipe according to claim 1, characterized in that on the outer surfaces of the protective sleeves in contact with the inner surface of the pipe, annular protrusions are made in the form of a triangle or trapezoid with a slope of the sides relative to the axis of the pipe at an angle α <90 ^o .
3. The pipe according to claim 1, characterized in that the wall thickness of the protruding ends of the protective sleeves is determined by the formula:
S _in = S _t $\genfrac{}{}{0ex}{}{\text{t}}{\text{t}}$ / σ $\genfrac{}{}{0ex}{}{\text{in}}{\text{t}}$ ,
where S _in - wall thickness of the protruding end of the protective sleeve;
S _t - pipe wall thickness;
σ $\genfrac{}{}{0ex}{}{\text{t}}{\text{t}}$ - yield strength of the metal pipe;
σ $\genfrac{}{}{0ex}{}{\text{in}}{\text{t}}$ - yield strength of metal protective sleeve. 4. The pipe according to claims 1 and 3, characterized in that the protective sleeve is made with an inner cladding layer of corrosion-resistant metal and the wall thickness of the protruding ends of the protective sleeve is determined by the formula:
S _in = (S _t $\genfrac{}{}{0ex}{}{\text{t}}{\text{t}}$ -S _p $\genfrac{}{}{0ex}{}{\text{P}}{\text{t}}$ ) / σ $\genfrac{}{}{0ex}{}{\text{in}}{\text{t}}$ ,
where S _p - wall thickness of the cladding layer of corrosion-resistant metal;
σ $\genfrac{}{}{0ex}{}{\text{P}}{\text{t}}$ - yield strength of the corrosion-resistant metal of the cladding layer.