Technical info - Steel galvanized pressed and welded grating

Technical Info on Grating

Deviation from geometric dimensions

Maximum difference between diagonals:

D1 – D2 = 0,01xS ( S – maximum side length)
Deviation by length and width:

f = max + 0 mm. to – 4 mm.

Cell Step Tolerances:

g = max +- 1,5 mm.

d = max +- 1,5 mm. (for 10 cells)

Technological cutout:

h, i = max + 8 mm. до – 0 mm.

Deviation from the plane within the grating:

Maximum deviation – 2 mm.

a = max 0,0025 x S

Maximum deviations

By concavity:

for bearing bar – max = 1/200 of the bearing bar length

for covering bar – max = 1/200 of the bar length

at sizes up to 600 mm. – no more than 3 mm.;

at the sizes more than 600 mm. – no more than 8 mm.

By concavity:

for the carrying bar – xt max = 1/200 of the bar length;

for covering bar – хg max = 1/200 of the bar length;

at sizes up to 600 mm. – no more than 3 mm;

at the sizes more than 600 mm. – no more than 8 mm.

Deviation of the carrying bar from the vertical:

Р max = 0,1 х Н (but no more than 3 mm)

The protrusion of covering bars:

The maximum protrusion of the covering bars over the bearing bars is Q max = 1.5 mm

Protrusion of framing:

The maximum protrusion of the framing bar over the bearing bar is S max = 1.5 mm

Lowering of framing:

The maximum lowering of the framing bar relative to the bearing bar is R max = 1.5 mm

Bevel cut:

Bevel cut relative to the vertical bearing bars – t max = + -0,1 x H mm (but not more than 3 mm)

Options of set

The grating should be placed from the edge of the supporting beam at a distance of 10 mm. The length of the supporting part of the grating is, as a rule, equal to the height of the grating but not less than 30 mm.

Plates of grating are laid back to back or with a gap of up to 4 mm.

When laying the grating in a corner frame, a gap of 5 mm should be provided on each side, but not less than the radius of the cornering of the angle.

With an angled frame of the grating, a gap of 5 mm is provided on each side, but not less than the radius of the cornering of the angle.

If on the structure of the support beam along the boundaries of the layout of the grating there are elements of equipment, or some structures, the grating is located at a distance of min. 10 mm.

With a cantilever arrangement of the grating, the distance from the obstacle is 10-50 mm. The grating console should not exceed 300 mm.

If the distance between the grating and the nearest obstacle is more than 50 mm, but less than 300 mm, the border bar on the obstacle side is replaced by a guard floor plate 180 mm high.

When the distance between the grating and the nearest obstacle is more than 300 mm., an additional installation of fencing with handrails and a 150 mm floor plate is required at a distance of up to 6 mm above the grating.

In the case of passage of pipelines or equipment through the grating, the distance between the grating and the pipeline or equipment should be up to 50 mm. (taking into account movement and isolation), unless otherwise is provided by the project.

In the case of passage of pipelines or equipment through the flooring, the distance between the grating and the pipeline or equipment should be up to 50 mm. (taking into account movement and isolation), unless otherwise is provided by the project.

Types of framing of grating

Type A

Standard framing
The height of framing is equal to the height of carrying bar.

Тип В

Undercut framing
Cutout is done in the lower part of the carrying bar in order to equalize the height of the grating with the surrounding level. Inspection of load characteristics is mandatory.

Type B1

Undercut framing (Reduced height)
The height of the frame is less than the height of the carrying bar by 5 mm. It is used in the fields where rounded surfaces are (e.g., angles).