USCG: What to know when testing alternate components for a type-approved BWMS

The Coast Guard’s Office of Operating and Environmental Standards issued a Policy Letter informing about the testing and validation of alternate components requested to be used with a type-approved Ballast Water Management System (BWMS).

According to USCG’s type approval regulations, a BWMS must meet to obtain type approval (46 CFR 162.060).

However, it is stated that in an increased rate, manufacturers include alternate components in the system bill of materials to give their customers more options for the wide range of circumstances under which BWMS are used.

Alternate components include any components not listed in the BWMS Operation, Maintenance, and Safety Manual (OMSM). The only alternate components addressed by this policy letter are filters.

The policy letter advises that the manufacturer should identify all the differences between the primary filter and all proposed alternate filters to facilitate the design study. The IL should then review the information provided and conduct a design study to assess equivalence to the original filter and compatibility with the overall BWMS. This design study should include comparisons of the following:

1. General arrangement of the system and filter interface;
2. Filter mesh type, rating, material, and design specification (ASME, ISO, etc.);
3. Rated minimum and maximum flow of each filter as identified by the manufacturer;
4. Minimum and maximum operating pressures of each filter;
5. Differential pressure across the clean filter at maximum flow rate;
6. Differential pressure set point to initiate the cleaning/back flush cycle;
7. Filter flow characteristics that note the effects of cleaning cycles on throughput and any other unique characteristics of the component;
8. Effective filtration area;
9. Filtration velocity (flow rate per square meter of effective filtration area); and
10. Backflush process characteristics (frequency, mode, etc.).

Therefore, instead of dictating specific testing protocols for individual alternate components, 46 CFR 162.060-16(c) defers the determination of testing requirements to the Coast Guard’s Marine Safety Center (MSC). In addition, an Independent Laboratory (IL), previously accepted by the Coast Guard under 46 CFR 159.010 must ensure that any alternate components meet the requirements of 46 CFR 162.060-34.

You may find more information by clicking on the Policy Letter herebelow