Define duration, location and module condition
Distinguish a short installed shutdown from long-term storage or transport of removed modules. Record the date, residual fouling, ambient temperature and frost exposure. If the restart date is uncertain, assign a responsible person and periodic checks rather than assuming protection will remain effective indefinitely.
Identify material, model, age and the current manual. The Inge documentation provides conditions for its own PES-UF family rather than every UF product. In particular, factory storage solution and preservation of a used membrane may require different preparation because they address different initial conditions.
Clean and preserve under an approved procedure
Deposits left in storage can make later recovery more difficult. Assess the cleaning required for the existing foulant and verify rinsing and compatibility before introducing preservative. Record chemical, effective concentration, volume, temperature and date. A container label alone does not establish the concentration inside the module.
Do not create a universal disinfectant mixture or use automotive antifreeze. The preservative must suit fibres, seals, potting and the intended water use. Specify which drains stay closed, which compartments must remain filled and how unauthorised oxidant exposure is prevented throughout the planned shutdown.
Inspect preservation during downtime
Check liquid level or full condition, leakage, temperature and the preservation parameters required by the procedure. An apparently isolated line can slowly lose liquid. For removed modules, use the approved packaging and orientation, protect openings and prevent stress on connectors. Record drying, impact or out-of-range temperature events.
Freezing protection must cover transport, storage and cold points on the skid, not just the main room. A protective compound may require a specified concentration and subsequent rinse. Obtain written instructions for the expected combination of conditions and monitor compliance throughout the period out of service.
Plan restart around measurable quality criteria
Before delivering useful water, inspect connections and complete filling, venting and rinsing according to the procedure. Manage preservative and initial filtrate based on their composition. Verify chemical removal against the agreed criterion and check integrity where appropriate. Smell and visual clarity do not replace the required measurements.
Record reference flow, TMP and normalised permeability and compare them with the earlier baseline. If drying or freezing occurred, contact the supplier before increasing pressure. Allow time for checks and a defined destination for initial water in the restart schedule and standby-capacity assessment.
Common questions
Is draining UF enough before freezing weather?
Not necessarily. Water can remain in pores and internal spaces, while drying a membrane that must stay wet can also cause damage.
Can production resume directly after preservation?
No. Follow the applicable filling, rinsing, quality and integrity checks for the actual preservative and module.