Membrane Module Warranties for Non-Proprietary MF/UF Systems - How They Work

I have often had questions from engineers and owners about how the MF/UF membrane module warranty is provided when the manufacturer of these membranes is different from the manufacturer of the membrane system. This confusion is understandable since traditionally the suppliers of low-pressure membrane systems (Pall, Siemens/Evoqua, GE) have also supplied their own proprietary membranes (Pall does not manufacture its MF membranes, but has exclusive access to Asahi’s Microza membranes in North America and some other regions). Therefore in the past, the membrane system warranty and membrane module warranty have originated from the same entity.

Wigen Manufactured UF Skid with Toray Modules

With the emergence in recent years of non-proprietary MF/UF systems built by companies such as Wigen Water Technologies and H2O Innovation that use ultrafiltration modules provided by companies such as Toray, Dow and Hydranautics, the question is often raised as to who provides the membrane module warranty and who does the customer call if there is a warranty issue?

The process of providing the extended membrane module warranty is not unlike that which has been in place for RO membrane elements for many years, although of course there are a lot of different and more complex requirements for a hollow fiber MF/UF membrane warranty. Typically, when an OEM is reviewing specifications for a MF/UF system, the OEM will share with the membrane module manufacturer (MMM) the proposed system design including design flux and cleaning regimes and water quality data along with the warranty requirements. In many cases the MMM will also provide a projection for the proposed plant design. Based on this information, the MMM will provide to the OEM a warranty that meets the requirements of the specifications or in some cases may provide some exceptions. This warranty is based on an agreed system design between the MMM and OEM. In my experience, the MMM will not provide the OEM with an extended warranty without reviewing the relevant sections of the specifications and the OEM’s proposed design. This warranty is then passed through the OEM to the system owner. Any warranty claims for both the membrane equipment and membrane modules are made direct to the OEM, as is also the case for the proprietary membrane system suppliers.

Therefore, as far as the system owner is concerned, the membrane module warranty provided for non-proprietary MF/UF systems is no different from what has been provided in the past for proprietary systems, with all claims made to the MF/UF system manufacturer (OEM).