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Stainless U bend tubes

Stainless steel u bend tube are widely used in heat exchanger systems. Heat exchanger equipment on the basis of stainless steel u-tube is essential in strategically important and critical fields nuclear and petrochemical machine building.

Please send your inquiry by   sales@sunnysteel.com

Description

Stainless steel u bend tubes are widely used in heat exchanger systems. Heat exchanger equipment on the basis of stainless steel u-tube is essential in strategically important and critical fields nuclear and petrochemical machine building.

Our u bend tube tube-bending production line, installed at 2007. Solution annealing after bend will be process to lower the residual stress, and followed by hydrostatic testing and dye penetrant testing if required.

Surface condition finished u bend tube shall be free of scale, without scratches after bending

Dimensional tolerances U Bend Tube acc. to TEMA R.C.B. and ASTM A566, ASTM A688

Diameter of tube in the U bent portion

At the bent portion of a U-tube for R = 2 × D or greater, neither the major nor minor diameter of the tube shall deviate from the nominal diameter prior to bending by more than 10 %.

If less than 2 × D is specified, tolerances could be greater, provided that Entropie agrees prior to order.

Wall thickness in U bent portion

The wall thickness of the tube in the U-bent section shall not be less than value determined by the equation:

wall thickness in u bent portion

Where:

  • tf wall thickness after bending, in. [mm],
  • T specified minimum tube wall thickness, in. [mm],
  • R centerline bend radius, in. [mm], and
  • D nominal outside tube diameter, in. [mm].

Tube leg length

In the case of U-tubes, the length of the tube legs as measured from the point of tangency of the bend and the tube leg to the end of the tube leg, shall not be less than specified, but may exceed the specified values by the amount given here below :

Leg length [mm]

Up to and incl. 6000 mm : -0 / +3.2 mm

Over 6000 mm to 9000 (incl) : -0 / +4.0 mm

Over 9000 -0 / + 4.8 mm

Difference in leg length

Stainless Steel Tube U Bend | U Bend Heat Exchanger TubesThe difference in lengths of the tube legs of a U tube shall not be greater than 1⁄8 in. = 3.2 mm unless otherwise specified.

End of tube : squareness

The end of any tube may depart from square by not more than:

0.25 mm for tubes up to 5/8” [15.9 mm]
0.40 mm for tubes higher than 5/8” [15.9 mm]

Leg spacing

The leg spacing measured between the points of tangency of the bend to the legs shall not vary from the value (2 R − specified tube outside diameter) by more than 1⁄16 in.[1.5 mm] where R is the center-line bend radius.

Bent portion curvature

The bent portion of the U-tube shall be substantially uniform in curvature, and not to exceed 6 1⁄16 in. [1.5 mm] of the nominal center-line radius.

Deviation from the plane of bend

Permissible deviation from the plane of bend (Fig. 1) shall not exceed 1⁄16 in. [1.5 mm] as

measured from the points of tangency.

The dimensions for heat exchanger tube in special grades may differ from the above,please contact us.

The advantage of the shell and tube design cannot be ignored. Each unit comes with:

  • Connections that come in standardized sizes for easy assembly and feature additional thread and surface protection for clean installation
  • U-bend tubes expanded into a tubesheet which allow for tube expansions and contractions due to thermal fluctuations.
  • Gaskets that are made of high quality compressed fibres which lends to reusability.
  • A standard cast-iron or steel head for heavy duty services (also available as a spare part).
  • Saddle attaches which make for quick and easy mounting.
  • Punched baffles with minimal clearances between tubes guaranteeing correct fluid flow and minimized bypass
  • A welded shell protected with high quality paint for corrosion resistance.
  • Copper steel tubes which allow for strong, durable performance over a wide range of applications. Unique tube bundle layout (chevron corrugated pattern) minimizes deposit buildup at the edges and optimises media flow for high velocity flow turbulence.