Storage of New RO Elements (Manual)

May 29, 2021


General Guidelines

TORAY RO elements must be preserved in a solution to prevent biological growth on membrane surfaces during storage and performance loss in a subsequent operation.
Element preservation is necessary for:
    •     Long term storage of new and used elements
    •    RO system shutdown ≥ 24 hours
If the RO elements have been in service, see “TMM-240 Shutdown considerations for RO systems” stated in “Toray RO Handling Manual”. 

Storage of New Elements

Store new elements in its original packaging until installing membrane elements into the pressure vessels for system startup. Recommended storage conditions are listed below:

1.    Store elements in a cool and dry place inside a closed building. Keep elements away from exposure to direct sunlight.

Note: New elements are packaged with a preservative solution made of 0.5–1.0% sodium bisulfite or sodium chloride, and a deoxidizer packet.

2.    Elements must be stored within a temperature range from freezing point to 35°C (95°F).

3.    Oxygen impermeable plastic bags under a slight vacuum are used for packaging new elements. The elements are shipped in durable carton boxes. Store the elements in the original shipping cartons until they are installed in the RO system's pressure vessels. Dispose of used bags and deoxidizers as regular municipal solid waste.

4.    Do not stack more than five rows of carton boxes when re-stacking from originally delivered packing (export packing).

5.    Please keep the original element packaging dry at all times to preserve structural integrity.

The data and information contained in this document are based upon rigorous technical testing by Toray, and is to the best of our knowledge reliable. Toray cannot control design and operating conditions, and consequently Toray does not assume any liability for results obtained or damage incurred through the application of the information provided herein. No liability, warranty or guarantee of final product performance by Toray is implied by the information provided in this document.
This manual supersedes all previous versions. Technical modification of products or production technology may necessitate changes to information in this manual without prior notice. Please verify that your version of the manual is the latest version available by either contacting Toray, or checking online at

This content is extracted from Toray’s “Toray RO Handling Manual (Version. Apr. 2021)” (the Manual). Please refer to other contents stated in the Manual. When using this content, please read the Terms and Conditions of Use stated in the manual and agree to them before using this content.