Fast Loop Filters (All Models)

Description

Fast Loop Filters are engineered to minimize the time delay commonly associated with online analyzer sample systems. Unlike traditional three-port T-type designs, our Fast Loop configurations continuously flush the filter element of heavy contaminants while filtering only the sample stream. This design significantly reduces lag time and extends filter element life.

Principle of Operation:
Fast loop filtration employs a high-flow bypass stream to continuously sweep contaminants away from the filter element, while only a small portion of the flow is directed through the element for analysis. This method is particularly effective for applications with heavy particulate loading or where sensitive analyzers require maximum protection from contamination.

Axial velocity within the housing carries bulk contaminants through the fast loop and back to the process stream. The sample stream passes radially through the filter element wall at a lower flow rate, maintaining a clean-side volume that is minimized to reduce lag time and enhance response accuracy.

Performance Recommendation:
For optimal operation and extended element life, a minimum 4:1 flow rate ratio between the bypass and sample streams is recommended to maintain continuous flushing and prevent element fouling.

Fast Loop Filter Design

The 126IL-3, 127IL-3, 136IL-3, and 146IL-3 models are machined from solid bar stock, eliminating welds and ensuring maximum durability. These housings are rated for 5,000 and 1,500 PSIG respectively, providing reliable performance in demanding applications.

Our 150IL-3 model is designed with a three-piece construction to reduce overall weight and simplify element maintenance. Both end caps are threaded to the filter body, making servicing quick and efficient.

Additionally, our SG137 and SG147 models feature a Pyrex bowl that allows for direct visual monitoring of the process. In these configurations, the traditional drain port serves as the inlet, while the original inlet functions as the fast loop outlet.

Maintaining the Filter Element

Our stainless steel filter elements are ideal for Fast Loop service, offering excellent corrosion resistance and durability to withstand continuous flushing. A key advantage of stainless steel elements is their ability to be cleaned through back-flushing, extending service life. We offer seven standard filtration grades with 98% efficiency at the following micron ratings: 01, 03, 10, 25, 50, 100, and 200. Grade 25 (25 microns) is commonly used to protect sample flows from visible particulates, while Grade 03 is recommended for removing pipe scale from steam lines.  PTFE sintered elements are recommended in applications where sample compatibility is a concern or when PTFE Fast Loop housings are employed.