Frequently Asked Questions

Bottle Sizing Service - General

- For questions on Level 1 bottle sizing, click here
- For questions on Level 2 bottle sizing, click here
Many packagers, owners and EPCs have requested that Wood VDN provide a sizing program for pulsation bottles. They require a better sizing program for these reasons:



While simple spreadsheets are available for preliminary sizing, our customers are concerned that these programs are out-of-date and have technical limitations. This creates risks and extra costs for their projects.

Packagers want to shorten the cycle time for manufacturing compressor packages. To achieve this goal, they must order bottle shells and heads early in the process. By using Bottle Sizing Service Level 2, packagers can now quickly define the final bottle sizes and order these long lead time components – saving valuable fabrication time.

When an existing compressor is being modified (retrofit project), there is risk that the new conditions and configuration will create pulsation and vibration problems. Bottle Sizing Service Level 2 determines if pulsation bottles must be changed for retrofit projects. We invite you to try the service – and look forward to your comments or suggested improvements. Please contact our application staff if you have any questions.
We invite you to try the service – and look forward to your comments or suggested improvements. Please contact our application staff if you have any questions on these programs.

Level 1: This is a basic sizing program, useful for the initial layout and bidding on a compressor project. It is quick and easy to use, especially for a limited number of operating conditions. Level 1 provides bottle sizes for non-critical applications where there is lower risk of vibration or reliability issues).

Limitations for Level 1: Bottle sizes may change once a pulsation study is performed. Not applicable for final sizing on critical applications, or where optimized bottles are required (low pressure drop and pulsation-induced forces across many conditions).

Level 2: This service is recommended when:
  • Final bottle sizes are required, allowing long lead time components, such as shells and heads, to be ordered. It also ensures the bottles will meet API 618 guidelines (pulsation-induced forces, pressure drop).
  • Many operating conditions need to be assessed. Operating conditions include the range in suction and discharge pressures, temperatures, and speed. This service accommodates up to 20 conditions (if more required, contact Wood VDN for a pulsation study).
  • Pulsation bottle internal design and cylinder nozzle orifice plate sizing is required.

Click to view the Features of Level 1 and Level Service.

If pulsation bottles are sized too large, the risks are:
  • More difficult mounting and supporting requirements for large bottles.
  • Higher capital costs for material and fabrication of large bottles.

If pulsation bottles are sized too small, the risks are:
  • Reliability concerns if there are excessive pulsations and vibrations.
  • Reduced performance and higher operating costs caused by excessive pressure drop.
  • Higher capital costs if secondary volumes are required.

In rare cases, a mini pulsation study is not adequate to properly size bottles. Instead, a full pulsation study is required. This limitation could apply to specialty gas compositions and very high pressures.

Customers receive full credit of the Level 2 service if a Wood pulsation study is undertaken for the project within one year of receiving the report for the Level 2 analysis. Using your personalized project database, locate the Wood VDN reference number (or tracking number) and include it when you order your pulsation study.

You can view your projects, including both Level 1 and Level 2 services through My Previous Projects. Select a project from the list and open it to be redirected to the appropriate page.

To update a Level 1 project, simply update the information in the Level 1 bottle sizing input page and click Calculate Bottle Sizes. To create a different project, remember to change the name in the "Reference" field.

To add or update information in your submitted Level 2 project(s), you will need your tracking number (or Wood VDN reference number). Simply send an email to, or call us at (+1) 403-245-5666 (Mountain Standard Time).

A Level 1 study is free. Click here for the Level 2 fee schedule.

Customers purchasing products or services must email a valid purchase order to, or contact us if payment by credit card or blanket service agreement is preferred.

Make purchase orders out to:
- For customers located in the US: BMA Solutions L.P., 17325 Park Row Drive, Houston, TX 77084, USA.
- For customers located outside the US: Wood Group Asset Integrity Solutions, 118, 4242 7th Street SE, Calgary, AB T2G 2Y8, CANADA.

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