Zinc Plating, Acid Chloride
Typical pH: 3.5 to 5.8
Temperature: 70 to 115 F (22 to 46 C)
Agitation: Mild to moderate
In-Tank Filtration: Well-maintained baths with modest production throughput may generate moderate amounts of solids. However, dropped parts, iron filings from work rotating in barrels, and drag-in from acid pickling all can cause formation of iron precipitates, which may be manifested as a pasty or muddy substance that can clog filter cartridges rapidly.
Carbon Treatment: As needed
Pump Material of Construction: CPVC usually specified. Polypropylene also good but costs more. Internal titanium shaft recommended for low-pH formulations.
Commonly Used Filter Cartridges: If the bath generates lots of solids, most users start with the FK50 Poly-Spun Disposables or the PMCXF (30-micron) Permacore Super Magnum Reusables in the required length. If the bath does not generate heavy solids, users generally start with the FK20 Poly-Spun Disposables or the PMCA Permacore Magnum Reusables. Depending on the solids generated, it may be necessary to switch to coarser cartridges (higher micron rating) to remove larger particles or finer cartridges (lower micron rating) to remove smaller particles. If reusable filter cartridges are preferred and a muddy residue is generated, some customers find it necessary to soak the filter blankets overnight in a dilute muriatic acid or other solution. This helps to break down the solids before immersion or spray cleaning with water. 
Special Notes: Because this may be a harsh environment, the pump must be mounted in a well-ventilated location for maximum motor life. The pump must not be installed in front of the ventilation exhaust, as this will expose the motor to a continuous draft of corrosive fumes.  

Zinc Plating, Alkaline Non-Cyanide
Typical pH: 12 to 13
Temperature: 75 to 105 F (25 to 41 C)
Agitation: Mild to moderate
In-Tank Filtration: General cleanliness.
Carbon Treatment: As needed
Pump Material of Construction: Polypropylene is strongly preferred. CPVC often become brittles, then cracks and splits, in this highly caustic solution.
Commonly Used Filter Cartridges: Most customers start with the FK20 Poly-Spun Disposables or the PMCA Permacore Magnum Reusables in the required length. Depending on the solids generated, it may be necessary to switch to finer cartridges (lower micron rating) to remove smaller particles.

Zinc Plating, Cyanide
Typical pH: 12 to 13
Temperature: 75 to 105 F (25 to 41 C)
Agitation: Mild
In-Tank Filtration: Used for the removal of anode sludge and to avoid shelf roughness. Note: Cyanide-containing baths are sensitive to aeration (especially surface bubbling). Excessive breaking of the wetted surface dissolves carbon dioxide from the atmosphere, causing carbonate formation. Therefore, the pump model and pump body length must be properly sized to avoid over-agitation and excessive turbulence at the solution surface.
Carbon Treatment: As needed
Pump Material of Construction: Some customers are able to use CPVC, though it may become brittle, then crack and split, over time in this highly alkaline solution. Polypropylene is preferred but costs more.
Commonly Used Filter Cartridges: Most customers start with the FK20 Poly-Spun Disposables or the PMCA Permacore Magnum Reusables in the required length. Depending on the solids generated, it may be necessary to switch to finer cartridges (lower micron rating) to remove smaller particles.

Zincate
Typical pH: 11+
Temperature: Room temperature to 90 F (32 C)
Agitation: Mild
In-Tank Filtration: In addition to general cleanliness, in-tank filter systems promote temperature/chemical homogeneity and uniform coverage, even in areas with blind holes.
Carbon Treatment: None
Pump Material of Construction:Polypropylene is strongly preferred. CPVC often become brittles, then cracks and splits, in this highly caustic solution.
Commonly Used Filter Cartridges: Most customers start with the FK20 Poly-Spun Disposables or the PMCA Permacore Magnum Reusables in the required length. Depending on the solids generated, it may be necessary to switch to finer cartridges (lower micron rating) to remove smaller particles.