Corrosion Resistant Chemical Transfer Pump

The Corrosion Resistant Chemical Transfer Pump is purpose-engineered for one of the most demanding pumping environments: the transfer of aggressive, corrosive, and hazardous chemicals. Unlike standard industrial pumps that rely on cast iron or basic stainless steel, our chemical pumps are constructed from advanced alloys and fluoropolymer linings selected specifically for resistance to a wide range of corrosive media, including sulfuric acid, hydrochloric acid, nitric acid, caustic soda (sodium hydroxide), organic solvents, and aggressive chemical intermediates. The pump design prioritizes safety, leak prevention, and long-term reliability in continuous chemical processing service.

The heart of corrosion resistance is material selection. Our pumps are available in five primary material grades, each suited to different chemical environments. Stainless Steel 304 (SS304) provides good resistance to nitric acid, organic acids, and mild alkalis at moderate temperatures – suitable for less aggressive chemical service. Stainless Steel 316 (SS316) adds molybdenum, improving resistance to chlorides, sulfuric acid, and many industrial chemicals; it is the standard choice for most chemical transfer applications. Stainless Steel 316L (low carbon) provides enhanced resistance to intergranular corrosion after welding, essential for welded piping systems.

For the most aggressive chemical environments, we offer high-performance alloys. Hastelloy C276 provides exceptional resistance to wet chlorine, hypochlorite, ferric chloride, and mixed acids – it is virtually immune to pitting and crevice corrosion in most aggressive environments. Titanium (Grade 2 or Grade 12) offers outstanding resistance to chlorides (including seawater), oxidizing acids (nitric, chromic), and wet chlorine; it is the material of choice for chlor-alkali and desalination applications. Duplex and Super Duplex (2205, 2507) provide high strength and good chloride resistance at a lower cost than titanium.

For extreme chemical resistance combined with economy, we offer fluoropolymer-lined (PTFE, PFA, or PVDF) construction. In this design, a carbon steel or ductile iron outer casing provides structural strength, while an internal lining of fluoropolymer (typically 3-5mm thick) provides chemical resistance. PTFE (polytetrafluoroethylene) is chemically inert to virtually all chemicals except molten alkali metals and fluorine gas at high temperatures. PFA (perfluoroalkoxy) provides similar chemical resistance but is more suitable for higher temperatures and has a smoother surface. PVDF (polyvinylidene fluoride) offers excellent resistance to acids, alkalis, and solvents at a lower cost than PTFE.

The pump hydraulic design is a single-stage, centrifugal type with an enclosed impeller. The impeller is of the open or semi-open type for lined pumps, as the thickness of the lining affects internal clearances. For alloy pumps, enclosed impellers with close-clearance wear rings provide maximum efficiency. All wetted components – casing, impeller, wear rings, and fasteners – are manufactured from the selected corrosion-resistant material. Non-wetted components (bearing housing, motor adapter, baseplate) are constructed from painted carbon steel or stainless steel.

Shaft sealing is critical in chemical service to prevent leakage of hazardous fluids. We offer multiple sealing options. Single mechanical seals with silicon carbide faces and FKM or FFKM elastomers are suitable for many chemicals at moderate pressures and temperatures. Double mechanical seals (API 682 Arrangement 2 or 3) with a pressurized barrier fluid (Plan 53) provide zero leakage to the atmosphere and are mandatory for toxic, carcinogenic, or highly hazardous chemicals. Magnetic drive (sealless) construction eliminates all dynamic seals entirely – the impeller is driven by a magnetic coupling through a containment shell. This provides absolute zero leakage and is ideal for volatile organic compounds (VOCs), toxic chemicals, and expensive fluids where any loss cannot be tolerated. For lined pumps, we also offer gland packing as a low-cost option for non-hazardous chemicals.

The pump's bearing system is isolated from the pumped fluid by the mechanical seals. Bearings are housed in a separate bearing bracket with oil or grease lubrication. For high-temperature service (above 120°C), we provide an air-cooled or water-cooled bearing housing to maintain bearing temperatures within acceptable limits. For pumps handling hot acids or hot caustic (up to 150°C), we recommend water-cooled stuffing boxes and high-temperature mechanical seals with suitable elastomers (FFKM or Kalrez).

Drive options include direct-coupled (C-face motor) or baseplate-mounted (flexible coupling) configurations. For hazardous areas, we supply explosion-proof motors (Ex d or Ex e) certified for Zone 1 or Zone 2 locations. For variable flow requirements, we offer VFD-ready designs with inverter-duty motors and reinforced insulation. For corrosive fume environments, we provide totally enclosed fan-cooled (TEFC) motors with special epoxy coatings (IEC 60092) to resist corrosion of the motor exterior.

Safety features include a integral drain port to allow complete pump draining before maintenance, a connection for a flush line to purge the seal chamber before seal replacement, and lifting lugs for safe maintenance access. For lined pumps, we incorporate a conductive carbon-filled PTFE layer in the lining to dissipate static electricity, essential for pumping flammable solvents.

Quality assurance includes 100% hydrostatic testing of all pressure-containing castings, positive material identification (PMI) of all alloy components to verify material grade, dye penetrant inspection of all welds, and performance testing to ISO 9906 standards. For fluoropolymer-lined pumps, we perform spark testing of the lining to detect pinholes or voids.

In summary, the Corrosion Resistant Chemical Transfer Pump provides safe, reliable, and long-lived service in the most aggressive chemical environments. With a wide range of alloys and lined constructions, we can offer a pump optimized for your specific chemicals, temperature, and concentration.