The longer 170L filter has twice the capacity of the standard 170, allowing for longer times between cleanings.
Unlike some filters, the element is completely cleanable and reusable and rarely needs to be replaced. OCV valves equipped with the Model 170 or 170L also have ball valves to enable isolation and cleaning of the filter. Ball valves are sold separately. The Model 170 and 170L are equipped with a convenient bleed port that allows for flow through and out of the filter for easy cleaning.