How to Descript the Construction Types and Flowing Direction of Wedge Wire Screen Tube?

When make description for wedge wire screen tube, often mention FOTI, FITO, Radial external wire, Radial internal wire, Axial internal wire. Some customers feel confused, we are pleased to make a simple and easy introduction for these parameters.

Flowing Direction-FOTI, FITO

• FOTI means flowing direction from outside to inside.
• FITO means flowing direction from inside to outside

Radial External Wedge Wire

Radial external wedge wire means the wedge wire is Radial outside the support wire, and the support profile wire is axial. These wedge wire tubes are composed of a surface wedge wire that is spirally wrapped around axial support profiles wire and attached to each other by resistance welding.

When the flowing direction is from outside to inside (FOTI), the flat side of the surface wedge wire is on the outside of the tube.

When the flowing direction is from inside to outside (FITO), the flat side of the surface wedge wire is on the inside of the tube. Radial external wedge wire FITO type also called reversed wedge wire screen tube.

Radial External Wedge Wire-FOTI

• Standard common type suitable for most applications
• Precision openings
• Economical production

Radial External Wedge Wire With Support Tube-FOTI

• External axial wire with internal circumferential support rods
• Optimized collection and distribution
• Replaces perforated inner tubes

Radial External Wedge Wire-FITO

• Also named reversed radial internal wedge wire
• Backwashing
• External circumferential inverted

Radial Internal Wedge Wire

Radial Internal wedge wire means the wedge wire is radial inside the support wire, and the support profile wire is axial.

Radial Internal wedge wire type tube is rolled formed from flat wedge wire screen panels, that means there are many welding joining points, the inside wedge wire is not continuously spirally wrapped around axial support profiles wires. And Radial Internal only have one flowing direction type that is FITO(flow in to out).

Radial Internal Wedge Wire-FITO

• Smooth internal screen surface
• Facilitates cleaning with an internal axial-movement scraper
• Economical easy for small quantity and any size production

Axial Internal Wedge Wire

Axial Internal wedge wire means the wedge wire is axial inside the support wire, and the support profile wire is on the outside of the filter element in a radial direction.

As the smooth surface of the wedge wire/profile wire is on the inside of the filter element, so that the filtration direction is from inside to outside.

That means, axial Internal wedge wire only have one flowing direction type that is FITO(flow in to out), although if FOTI(flow out to in) is also possible in exceptional cases.

And for Axial Internal Wedge Wire, according to different slots size, filter size, there are two different types, one type is wedge wire type tube or cylinder is rolled formed from flat wedge wire screen panels, that means there are many welding joining points. The other type is the support outside support wires is continuously spirally wrapped around axial wedge screen wires.

Axial Internal Wire-Welding Joint Support-FITO

• Smooth internal screen surface
• Facilitates cleaning with an internal axial-movement scraper
• The flow moves across the wire edges for effective dewatering
• Economical utility

Axial Internal Wire-Continuous Support-FITO

• Smooth internal screen surface
• Without a welding seam, more stronger strength
• Facilitates cleaning with an internal axial-movement scraper
• The flow moves across the wire edges for effective dewatering

Axial External Wedge Wire

Axial External wedge wire means the wedge wire is axial outside the support wire, and the support profile wire is on the inside of the filter element in a radial direction.

As the smooth surface of the wedge wire/profile wire is on the outside of the screen filter element, so that the filtration direction is usually from outside to inside. But sometime, the customers require Axial External Wedge Wire and FITO, that means the smooth surface of the screen wedge wire is inside. When no special requirement, say Axial External Wedge Wire that is FOTI.

Axial External Wedge Wire tube or cylinder is rolled formed from flat wedge wire screen panels, that means there are many welding points on the inner supporting profile wires.

Axial External Wedge Wire-FOTI

• Channel rod construction
• Economical and easy production
• Smooth surface outside

Inverse Axial External Wedge Wire-FITO

• Channel rod construction
• Smooth surface Inside
• Not commonly used