How to select a pump for 98% concentrated sulfuric acid, as well as the appropriate valves and pipes?

How to select a pump for 98% concentrated sulfuric acid, as well as the appropriate valves and pipes?

Under the action of 98% concentrated sulfuric acid, cast iron and carbon steel undergo passivation of their metal surfaces, allowing the formation of an oxide layer that is resistant to reactions, thereby achieving corrosion resistance. Therefore, it can be used as material for pumps, valves, and pipes to transport 98% concentrated sulfuric acid! :) However, it is absolutely forbidden to use external flushing water for the mechanical seal of the pump, as this water will dilute the concentrated sulfuric acid; the resulting localized dilution of the acid will destroy the passivation layer on the metal, leading to corrosion! Just trying to stimulate further discussion; looking forward to better answers! :)

Valves with full lining or plastic valves would be more suitable! I can handle that! QQ: 928976489

A standard chemical process centrifugal pump will suffice; the material commonly used is 20# alloy. Our company usually purchases pumps from Xiangfan 525. Additionally, the IEJ pump models from Zhangjiagang are also good, but it’s advisable to choose seals of high quality. Valves generally use fluorinated-lined valves or carbon steel globe valves; carbon steel pipes are sufficient for the pipelines

1. Concentrated sulfuric acid, as one of the highly corrosive substances, is an important industrial material with a wide range of applications. Sulfuric acid at different concentrations and temperatures causes varying degrees of corrosion to materials. For concentrated sulfuric acid with a concentration of over 80% and a temperature below 80°C, carbon steel and cast iron exhibit good corrosion resistance; however, it is not suitable for sulfuric acid that flows at high speeds, and it cannot be used as material for pumps and valves ； Common stainless steels such as 304 (0Cr18Ni9) and 316 (0Cr18Ni12Mo2Ti) also have limited utility in sulfuric acid media. Therefore, pump valves for transporting sulfuric acid are usually made of high-silicon cast iron (which is difficult to cast and machine) or high-alloy stainless steel (grade 20 alloy). Fluoroplastics exhibit good resistance to sulfuric acid, making the use of fluorine-lined pumps (F46) a more economical option. Applicable pumps include: IHF fluoroplastic chemical pumps, PF(FS) highly corrosion-resistant centrifugal pumps, CQB-F fluoroplastic magnetic pumps, etc. 2. Valve selection for concentrated sulfuric acid transport pipelines in general sulfuric acid production enterprises: In the past, many enterprises used cast-iron valves; nowadays, for diameters larger than Dg50, fluoroplastic-lined butterfly valves are generally used ； For values less than Dg50, stainless steel ball valves are generally used; stainless steel globe valves are also used (but less frequently).

Our unit uses carbon steel; concentrated sulfuric acid causes little corrosion to carbon steel, so it usually holds up for 7 or 8 years without problems. However, it’s better to use seamless steel

For pumping concentrated sulfuric acid, fluoroplastic magnetic pumps are the preferred choice. Mechanical seal pumps used for transporting concentrated sulfuric acid will experience leakage in about five to six months, which is quite troublesome.