Skip to main content

Straightening Vane

 

Straightening vaneA straightening vane is used in pipelines to promote a more uniform and streamlined flow of liquid to straighten the gas flow before going into a gas meter to ensure accurate measurement.  Its purpose is to reduce turbulence and irregular flow patterns within the pipeline, enhancing the efficiency of fluid transportation.  When installed upstream with the correct pipe length, it will reduce the turbulence before entering a metering devise such as an orifice flanges or flow meter.  This will insure a more accurate meter reading.

One type can be held between two flanges and another secured inside the pipe with set screw on the outside.  These devices are often employed in situations where maintaining a smooth and consistent flow is crucial for the proper functioning of the pipeline system.

Straightening vane dia 1Functions of a Pipeline Straightening Vane

Turbulence Reduction  -  The primary function is to minimize turbulence caused by factors such as changes in pipeline direction, fittings, or other flow disturbances.
Improved Flow Profile  -  Straightening vanes help in establishing a more predictable and controlled flow profile within the pipeline, reducing swirls and eddies.
Energy Loss Reduction  -  By promoting a more streamlined flow, these vanes can contribute to reducing energy losses associated with turbulence, ultimately improving the overall energy efficiency of the pipeline.
Pipeline Efficiency  -  Straightening vanes are used in various industries, including oil and gas, water distribution, and chemical processing, where maintaining a consistent flow is critical for operational efficiency.
Straightening vane dia 2Design Variations  -  The design of straightening vanes can vary based on the specific requirements of the pipeline system.  Some vanes may be stationary, while others may be adjustable to adapt to different flow conditions.

It's important to note that the application of straightening vanes is just one method to address flow irregularities in pipelines.  The choice of such devices depends on factors such as the type of fluid being transported, pipeline design, and operational requirements.  Consulting with experts in fluid dynamics, pipeline engineering, or the specific industry context is advisable for detailed and site specific information.

Straightening Vane Dimensions (in)

Pipe Size (NPS)

Bundle TypePipe I.D.Length of Vane AO.D of VaneBO.D. of TubesWall Thickness of TubesNumber of TubesNumber and Size of ScrewsApprox. Weight Flange Type(lb)Approx. Weight Line Type (lb)Flange O.D.

2

I

2.067

 6 1 - 31/32 21/32 .095 7 1 - 3/8 x 3/4 3 2 3 5/8

2

I

1.939

 6 1 - 29/32 21/32 .095 7 1 - 3/8 x 3/4 3 2 3 5/8

3

II

3.068

 8 2 - 7/8 19/32 .049 19 1 - 3/8 x 3/4 4 3 5
3 II 2.900 8 2 - 3/4 9/16 .049 19 1 - 3/8 x 3/4 4 3 5
4 II 4.026 10 3 - 31/32 13/16 .049 19 1 - 3/8 x 3/4 8 7 6 - 3/16
4 III 3.826 10 3 -  3/4 3/4 .049 19 1 - 3/8 x 1 8 7 6 - 3/16
5 II 5.047 12 4 - 27/32 1 .049 19 1 - 1/2 x 1 11 9 7 - 5/16
6 II 6.065 12 5 - 15/16 1 - 7/32 .049 19 1 - 1/2 x 1 21 19 8 - 1/2
6 II 5.761 12 5 - 5/8 1 - 5/32 .049 19 1 - 1/2 x 1 21 19 8 - 1/2
8 II 7.625 16 7 - 15/32 1 - 1/2 .065 19 1 - 1/2 x 1 37 35 10 - 5/8
8 II 7.981 16 7 - 29/32 1 - 5/8 .065 19 1 - 1/2 x 1 37 35 10 - 5/8
10 III 10.136 20 10 2 .083 19 1 - 1/2 x 1 57 54 12 - 3/4
10 II 10.020 20 9 - 3/4 2 .083 19 1 - 1/2 x 1 57 54 12 - 3/4
12 III 12.090 24 11 - 7/8 2 - 3/8 .083 19 2 - 1/2 x 1 - 1/4 81 77 15
12 III 11.374 24 11 - 1/4 2 - 1/4 .095 19 2 - 1/2 x 1 - 1/4 81 77 15
12 II 11.938 24 11 - 5/8 2 - 3/8 .083 19 2 - 1/2 x 1 - 1/4 81 77 15
14 III 13.25 28 13 - 1/8 2 - 5/8 .083 19 2 - 1/2 x 1 - 1/4 105 100 16 - 1/4
14 II 13 28 12 - 3/4 2 - 5/8 .083 19 2 - 1/2 x 1 - 1/4 105 100 16 - 1/4
16 III 15.250 30 15 3 .188 19 2 - 1/2 x 1 - 1/4 274 268 18 - 1/2
16 II 15.500 30 14 - 18/32 3 .188 19 2 - 1/2 x 1 - 1/4 274 268 18 - 1/2
18 II 16.876 36 16 - 23/32 3 - 7/16 .188 19 2 - 1/2 x 1 - 1/4 386 378 21
20 II 19.250 40 18 - 27/32 3 - 7/8 .188 19 2 - 1/2 x 1 - 1/4 477 468 23
24 II 23.250 48 23 - 1/8 4 - 3/4 .188 19 2 - 1/2 x 1 - 1/2 704 693 27 - 1/4
26 III 25.250 52 25 5 .188 19 2 - 1/2 x 1 - 1/2 814 796 29 - 1/2
30 III 29.250 60 28 - 3/4 5 - 3/4 .188 19 2 - 1/2 x 1 - 1/2 1295 1273 33 - 3/4
34 II 33.250 68 32 - 13/16 6 - 3/4 .250 19 2 - 1/2 x 1 - 1/2 1880 1860 38
36 III 35.250 72 35 7 .188 19 2 - 1/2 x 1 - 1/2 1582 1559 40 - 1/4

General Guidance in Determining Inlet and Outlet Distances

The calculation of the pipe inlet and outlet distances required for a straightening vane involves considerations related to fluid dynamics and the desired performance of the vane.  There is no universal formula for this calculation, as it depends on factors such as the type of fluid, pipe diameter, vane design, and the specific flow characteristics of the pipeline.

  • Inlet Distance
    • The purpose of the inlet distance is to provide sufficient length for the fluid flow to stabilize before reaching the straightening vane.
    • It helps in minimizing the impact of disturbances or swirls in the fluid before it reaches the vane.
    • The length of the inlet section may depend on factors such as the Reynolds number and the extent of flow disturbances in the upstream pipeline.
  • Outlet Distance
    • The outlet distance is essential for allowing the flow to fully adjust and stabilize after passing through the straightening vane.
    • It helps prevent flow disturbances downstream of the vane.
    • The length of the outlet section may depend on factors such as the vane design and the desired flow profile downstream of the vane.

While there isn't a specific universal formula for calculating these distances, you may need to consider factors such as the Reynolds number, pipe diameter, and the specific objectives of using the straightening vane.  For a more accurate and site specific calculation, it's recommended to consult with experts in fluid dynamics or pipeline engineering.  Computational fluid dynamics simulations may also be employed to analyze the flow patterns and determine the optimal distances for inlet and outlet sections based on the specific conditions of the pipeline.  Additionally, industry standards and guidelines may provide specific recommendations for the design of flow straighteners in certain applications.

Straightening Vane Standards

  • For fabrication requirements, see ASME MFC-3M

Piping Designer Logo 1