CHEMICAL CORROSION RESISTANCE

GL Chemical Resistance

Resistance to Acids

Generally, enamel has a good resistance to acids whatever their concentration up to relatively high temperatures.
H2SO4 30% : 128°C abrasion 0.1mm/year
H2SO4 60% : 180°C abrasion 0.1mm/year

Resistance to Alkalis

Here the permissible temperature limits are lower than for acids.
NaOH 1N : Max. Temp. 55°C

Resistance to boiling water

Resistance to demineralized water is excellent.(under 100℃)

DATA

The iso-corrosion curves reflect the ratio of product or acid volume to the enamelled surface in large stirring containers and yield experimental data according to DIN EN 14483-2 and 5.

Using the silica effect, Pfaudler World Wide Glass WWG can take much more chemical stress than the usual limits without any risk. The diagrams thus also show typical concentrations with added silicon dioxide as corrosion protection.

Dark-blue curve:
chemical effect of acids
on Pfaudler WWG does
not exeed 0.1 mm/a
thickness loss.
Light-blue curve:
represents the 0.2
mm/a curve and shows
the resistance capacity
of Pfaudler WWG with
regard to acreases in
temperature.
White dots:
indicate the increasing
enamel durability with
regard to non-inhibited acids.

Completely resistant VL≤ 0.1 mm/a

Limited resistance when subject to brief chemical stress VL= 0.1 … 0.2 mm/a

The iso-corrosion diagrams illustrate factors relevant to the corrosion rate. These include, for example, the volume/surface ratio, the base concentration and the temperature. All information in the diagrams refer to a technically pure base. The curves reflect experimental data according to DIN EN 14483-2 and 5.

The two upper diagrams are predominantly applicable to aqueous solutions containing alkali-hydroxide. The application temperature is restricted to 50˚C at higher concentrations.

Completely resistant VL≤ 0.1 mm/a

Limited resistance when subject to brief chemical stress VL= 0.1 … 0.2 mm/a

THE RATE OF ENAMEL LOSS 0.1MM IS NO PROBLEM.
THE RATE OF ENAMEL LOSS BETWEEN 0.1 AND 0.2MM CARE MUST BE TAKEN OF THE ADVANCE OF THE CORROSION.