Flat Welded Screens

General
Standard constructions of flat welded screens
Standard tolerances
Special executions
Finishing
Frames and Reinforcements
Final products manufactured with flat welded screens

General

Flat Welded Screens are structures where the surface profiles are welded at each intersection at 90° angles onto support profiles.

Trislot® Advantages

In contrast to flat screens (produced by opening and flattening a slot tube), Trislot® Flat welded screens are manufactured on dedicated welding machines. This results in the following advantages:

flatness to within tight tolerances
no weakening of the welds, because of flattening (and no stress corrosion problems as a result)
accurate distance between support profiles
possibility of different support wires in one screen
possibility of variable spacing between support wires in one screen

Trislot offers standard Flat Welded Screens in a large variety of surface and support wire combinations, that can be applied for simple screen plates to heavily reinforced reactor internals. The Trislot design team can also design screens tailored to your specific requirement.

Manufacturing method for Flat Screen

Trislot® manufacturing method for Flat Welded Screen

Standard constructions of flat welded screens

Flat Welded Screens with dimensions other than those given below are available on request.

The designation for a Flat Welded Screen is for instance: 22S/Q35 - 70

22S = surface wire
Q35 = support wire
70 = distance between support wires in mm

Profile combinations

Surface profiles	Support profiles	Min. Slot in mm	Standard pitch in mm (*)
12S/12SL	Q25/Q35	0.030	22
12S	Q35/10x3	0.100	35-100
18S	Q35/10x3/25x3	0.100	35-100/70
22S	Q35/10x3/25x3/50x3	0.120	35-100/70
28S	Q35/10x3/25x3/50x3	0.150	35-100/70
34S	Q35/10x3/25x3/50x3	0.150	35-100/70
42S	Q35/10x3/25x3/50x3	0.150	40-100/70
50S/50SC	10x3/25x3/50x3	0.150	45-100

(*) in most cases all pitches are possible
pitch = distance between support profiles

Dimensions

For pitch 22 mm:
- Max. surface profile length: 710 mm
- Max. support profile length: 1700 mm
For pitch 70 mm:
- Max. surface profile length: 2000 mm
- Max. support profile length: 2000 mm
For other pitches:
- Max. surface profile length: 3000 mm
- Max. support profile length: 3500 mm

Standard tolerances

Slot size: ± 0,050 mm (max. ± 0,1 mm)

Flatness for a screen without frames: 5 mm per meter

Length	Width
≤ 500 mm	± 2 mm
≥ 500 mm ≤ 1500 mm	± 3 mm
≥ 1500 mm	± 4 mm

Special executions

Support profile form and pitches

Trislot® unique production equipment allows special constructions of Flat Welded Screens with:

different support wires in one screen and/or
variable spacing between support wires in one screen

» Example of a cylinder made from a Flat Welded Screen with different support wire pitch.

Curved Screen

Trislot can bend a Flat Welded Screen to form a Curved Screen to fit your application. Tilting of the surface profile determines the filtration direction.

Finishing

Standard finish:
- cutting of width and length of Flat Welded Screen
Optional finish:
- deburring
- degreasing and pickling
- post-machining for tighter tolerances

» Example of a Flat Welded Screen cut into a round form

Frames and Reinforcements

Flat Welded Frames can be welded onto frames or be reinforced by Trislot. This is available on request.