General Galvanizing Line
Structural Steel Hot-dip Galvanizing
1. Introduction：
Tianjin Gongda has developed a range of hot dip galvanizing lines
to meet the needs of general galvanizers involved in galvanizing
electric power towers, telephone towers, street lighting poles,
guard rail and general items. These lines incorporate the best
available hot dip galvanizing technology and are designed to
exactly meet customers requirements and budgets.
In addition to supply, installation and commissioning Tianjin
Gongda offers ongoing technical support (Fee basis) to provide the
maximum economic benefits particularly in terms of zinc consumption
and waste treatment costs
The key characteristics of these lines are:
Rapid pickling with acid use as low as 15 Kg/tonne of work
Zero discharge rinse system eliminating the need for expensive
waste treatment
A Pre-flux system where a balanced salt state is maintained and the
ferrous iron concentration is consistently below 0.6 g/l to allow
enhanced management of the zinc kettle to yield reduced zinc uptake
and low dross and ash make
Galvanizing at a constant temperature to increase the life of the
kettle
Zinc kettle enclosures for fume extraction and protection against
splatter - both side and end entry available
Low-chrome passivation without discharge of hexavalent chrome.
2. Technology Conditions:
Materials to be galvanized：Steel segment, Q235B, Q345B
Temperature of molten zinc: 440℃～455℃
Pretreatment: Degrease with alkali acidic degreaser, pickle with
either HCl or H2SO4
Zinc composition: pure zinc/galfan & zinc-based multivariant
alloy.
Energy source: natural gas, diesel oil, coal gas, electricity.
3. Standards which can be met:
ISO1461：1999（E）GB/T 13912-2002 ASTM-A123
4. Major components Pretreatment Tanks;
Acid fume extraction and scrubbing; Waste heat recycling for
drying and heating of pretreatment baths;choice of GongDa ceramic
bath German steel zinc baths; Pre-flux iron removal equipment;
Cranes; Frequency Conversion Equipment.
High-carbon steel, spheroidal graphite iron, malleable cast iron
and carbon-steel iron nail hot-dip galvanizing line
1. Introduction：
The traditional galvanizing temperature is high, generally between
580℃～660℃. In this temperature range, zinc liquid is highly
corrosive towards steel and the life of a zinc bath (cast-iron) is
generally about 20 days. High dross and ash makes are additional
features. Tianjin Gongda has developed a low-temperature
galvanizing technique.
The major characteristics are:
The working temperature is between 450℃～470℃
A multivariant zinc alloy with Al, Si and Sn
Ceramic zinc bath
Immersion heaters to heat the zinc (overhead heating can be
supplied)
2. Technology conditions:
Materials to be galvanized: Hiigh-carbon steel, spheroidal
graphite iron, malleable casting iron, electric hardware and
standard components made from cast iron Temperature of molten zinc:
460℃～475℃
Pretreatment: shot blasting, degrease with acidic degreaser, pickle
with HCl
Zinc composition: pure zinc + zinc-based multivariant alloy.
Energy source: electricity
3. Technical standards which can be met:
Accord with ASTM－A385 GB/T13912-2002
4. Major equipment
Pedrail-type Abrator, Ring Jack, Pickling Equipment, Ceramic Zinc
Bath, Continuous Drying Equipment, Centrifug.
