KQWHZ series centrifugal pumps can be used to a certain extent in chemical industry, oil transportation, food, beverages, medicine, water treatment, environmental protection and some acids, alkalis, salts and other application fields according to the specific use conditions of the user. They are used to transport certain corrosive materials. , a medium that does not contain solid particles or a small amount of particles and has a viscosity similar to water. Not recommended for use in toxic, flammable, explosive, or highly corrosive situations.

(1) Nitric acid and applications in nitric acid industry

In the process of producing nitric acid by ammonia oxidation, the dilute nitric acid (50 to 60%) generated in the stainless steel absorption tower flows out from the bottom of the tower into the stainless steel storage tank, and is transported to the next process with a stainless steel pump. Pay attention to the medium temperature and inlet pressure here.

(2) Applications in phosphoric acid and phosphoric acid industry

For pure acid, chromium 13 stainless steel is only resistant to aerated dilute acid, and 18-8 chromium-nickel austenitic stainless steel is only resistant to aerated dilute acid. The best phosphoric acid-resistant material is chromium nickel molybdenum (0Cr18Ni12Mo2Ti) stainless steel. However, for the phosphoric acid production process, the material selection of the pump is much more complicated due to the corrosion problem caused by the presence of impurities in the phosphoric acid, and needs to be treated with caution.

(3) Application in sodium chloride and salt industry (brine, seawater, etc.)

Chromium-nickel stainless steel has a very low uniform corrosion rate at a certain temperature and concentration against neutral and slightly alkaline sodium chloride solutions, seawater and salt water, and is widely used. However, attention should be paid to the occurrence of dangerous localized corrosion in some cases. Stainless steel pumps are widely used in the food industry for handling brine and salted food. However, attention must be paid to media crystallization issues and mechanical seal selection issues.

(4) Application in sodium hydroxide and alkali industry

Chromium-nickel austenitic stainless steel can withstand sodium hydroxide of less than 40 to 50% to about 80°C, but it is not resistant to high-concentration and high-temperature alkali liquid. Chromium stainless steel is only suitable for low temperature and low concentration alkali solutions.

Attention must be paid to the problem of medium crystallization.

(5) Application in oil transportation

Attention must be paid to the viscosity of the medium, the selection of rubber parts, and whether the motor has explosion-proof requirements, etc.

(6) Application in pharmaceutical industry

According to the transmission medium of the pump, medical pumps can be divided into the following two categories: one type is ordinary water pumps, hot water pumps and wastewater treatment system pumps used in public projects; the other type is used to transport medicinal liquids, intermediates,

Pumps for process media such as pure water, acid and alkali. The former has lower requirements for pumps and can be handled by pumps used in general chemical equipment; while the latter has higher requirements for pumps, and the pumps must meet the technical requirements for centrifugal pumps used in medical equipment.

(7) Application in food and beverage industry

In the food and beverage industry, the medium is non-corrosive or weakly corrosive, but rust is never allowed. The purity of the medium is very high. In this case, a stainless steel pump can be used.

This series of pumps uses M3N or MG1 rubber bellows mechanical seals as mechanical seals based on specific usage conditions.

Normally, M3N type mechanical seals are widely used. It has high stability and good reliability, and is suitable for cleaning media without impurity particles. Mechanical seals can be used in some acid, alkali, salt, oil, beverage and organic chemical media applications through different combinations of materials of each component. Type MG1 mechanical seal is the most commonly used seal. Can be used in wastewater containing particles. Not suitable for use in organic solvent media.

According to the actual situation, the materials of each component of the mechanical seal can be selected as follows:

1. For the M3N series rotating ring materials available:

Antimony-impregnated graphite (A), resin-impregnated graphite (B), mounted pressureless sintered silicon carbide (Q12), mounted reaction sintered silicon carbide (Q22), mounted nickel-based tungsten carbide (U22), etc.

Optional stationary ring materials:

Pressureless sintered silicon carbide (Q1), reaction sintered silicon carbide (Q2), etc.

2. For the MG1 series rotating ring materials available:

Antimony-impregnated graphite (A), resin-impregnated graphite (B), pressureless sintered silicon carbide (Q1), etc.

Optional stationary ring materials:

Pressureless sintered silicon carbide (Q1), alumina ceramics (V), etc.

3. Auxiliary seal materials are available:

Ethylene-propylene rubber (E), nitrile rubber (P), fluorine rubber (V), etc.

The application temperature range of nitrile rubber is -54 ~ +120℃. It has good corrosion resistance to mineral oil, animal and vegetable oils and aliphatic hydrocarbons. Resistant to alkali and oxidizing dilute acid corrosion. Can be used at +100℃ for a long time. When selecting, please refer to Table 3 on the attached page of the sample.

The application temperature range of ethylene-propylene rubber is -60 ~ +150℃. Resistant to corrosion by dilute acids, alkalis, and salts, but not resistant to corrosion by oxidizing acids, aromatic hydrocarbons, and petroleum products. When selecting, please refer to Table 4 on the attached page of the sample.

Fluorine rubber is resistant to high temperatures and has excellent corrosion resistance. Resistant to various acids, alkalis, salts, and petroleum products. When selecting, please refer to Table 5 in the attachment of the sample.

4. The materials of springs and other structural parts can be selected from:

0Cr18Ni12Mo2Ti (G), 0Cr18Ni9 (F), 2Cr13 or 3Cr13 (F1), etc.

Chromium steel 2Cr13 or 3Cr13 is used in weakly corrosive media, and stainless steel (0Cr18Ni12Mo2Ti, 0Cr18Ni9) is used in more corrosive media.

In order to ensure the long-term reliable operation and normal maintenance of the pump unit, customers can purchase the following spare parts or accessories according to actual conditions. (see table below)

1. The performance parameters listed in the sample are only for clean water at normal temperature.
2. Users must be aware of the following factors when transporting non-aqueous media:

① Medium name and composition, operating temperature and temperature range, concentration and impurity content;

② Medium density and viscosity

When the viscosity of the medium is ≤ 20mm2/s, the performance parameters of the pump do not need to be converted;

When the viscosity of the medium is ≥ 20mm2/s, conversion is necessary.

The supporting motor power listed in the sample is based on normal temperature clean water. When the medium density is different from water, the supporting power needs to be recalculated

③ Toxicity, explosiveness, flammability;

④ Saturated steam pressure or inlet pressure;

⑤ Whether there are factors such as precipitation, crystallization or volatilization of the medium;

Customers must provide the above data or technical requirements truly and comprehensively, and fill in the relevant options in the “KQWHZ Centrifugal Pump Selection Technical Data Sheet” so that the manufacturer can correctly and reasonably select materials,

Sealing and matching motors also facilitate the manufacturer to further track and understand customer usage.

3. As part of the contract review content, the “KQWHZ Centrifugal Pump Selection Technical Data Sheet” will be archived for future reference after review and confirmation by the relevant department, and its copy will be issued together with the order.

Departments to organize production.

4.Special instructions are also required when there are special requirements for flow, head, inlet pressure, motor explosion-proof, etc.