Slots Versus Holes Improve Flow Through Safety Screens

Protecting components in critical fluids handling applications from the risks of blockages caused by unwanted contaminants is essential in helping to eliminate system failure and downtime. As a result of a special testing programme, The Lee Company is now able to offer custom designed safety screens with rectangular slots as an option instead of round holes. Tests revealed that HI-BAR safety screens with rectangular slots, as opposed to circular holes, provided significantly improved flow control. In the tests, two screens, one with 100u slots and one with 100u circular holes (with both screens having the same open area), were subjected to a flow test while introducing glass beads to simulate contamination. As the screens became clogged with the spherical particles, the results confirmed that the screen with the rectangular slots experienced a 50% less pressure drop compared to the screen with the holes.

Typical applications for this type of safety screen will include oil tool production where the likelihood of spherical particles (e.g. sand) could potentially lead to traditional types of safety screens clogging more easily than those with rectangular slots. Depending on size and material, they can withstand pressure differentials up to 7,500 psid, without rupture. The screens are manufactured in 17-4PH S/S with hole sizes ranging from 75 to 500 microns and are also available in brass for applications where resistance to corrosion and combustion is important and also in PEEK for use in medical and scientific applications. Custom designs are also available for more specific application requirements and the availability of rectangular slots significantly extends the capability of HI-BAR Safety Screens.