Dosing Pump Material Characteristic Comparison


With the rapid development of the energy-saving and environmental protection industry, sewage treatment has become increasingly important in the environmental protection industry. In sewage treatment, dosing pumps play a crucial role in dosing chemical treatment of sewage. When selecting a dosing pump, the acidity and alkalinity of the sewage determine the material of the pump head and diaphragm. Here let's get to know several common materials for doing pump heads and diaphragms. There are many choices for the material of dosing pump heads and diaphragms, but currently, the most widely used materials are PP, PVC, and PTFE.

Polypropylene (PP)

Polypropylene (PP) is a semi-crystalline thermoplastic. It has high impact resistance, strong mechanical properties, and resistance to various organic solvents and acid and alkali corrosion. PP is non-toxic, odorless, and has good electrical performance and high-frequency insulation. It is not affected by humidity. However, it becomes brittle at low temperatures, and is not abrasion-resistant and easy to aging. It is suitable for making general mechanical parts, corrosion-resistant parts, and insulation components. Common acid and alkali organic solvents have little effect on it, and can be used for food utensils and suitable for the treatment of sewage with slightly acidic, alkali yet prone to neutral nature.

Polyvinyl Chloride (PVC)

Polyvinyl chloride (PVC) is a thermoplastic resin formed by the polymerization of vinyl chloride under the action of initiators. It is a homopolymer of vinyl chloride. PVC is an amorphous white powder with a low degree of branching. It has good mechanical properties, with a tensile strength of around 60 MPa and an impact strength of 5–10 kJ/m2. It also exhibits excellent dielectric properties. However, it has poor stability to light and heat. PVC is rigid and has poor solubility, only soluble in a few solvents such as cyclohexanone, dichloroethane, and tetrahydrofuran. It is chemically stable against organic and inorganic acids, alkalis, and salts, but its chemical stability decreases with increasing temperature. PVC is difficult to ignite, acid and alkali resistant, antimicrobial, wear-resistant, and has good thermal insulation and elasticity. It is suitable for the treatment of sewage with a slightly acidic or alkaline nature.

Polytetrafluoroethylene (PTFE)

Polytetrafluoroethylene (Teflon or PTFE), commonly known as "plastic king", generally referred to as "non-stick coating" or "easy-to-clean cookware material", is a high polymer compound formed by the polymerization of tetrafluoroethylene. PTFE exhibits excellent chemical stability, corrosion resistance, sealing properties, high lubricity, non-adhesiveness, electrical insulation, and good resistance to aging. It is used as an engineering plastic and can be made into PTFE pipes, rods, tapes, sheets, and films. This material features its excellent resistance to acids, alkalis, and various organic solvents, and is virtually insoluble in all solvents. Additionally, PTFE has high temperature resistance and an extremely low coefficient of friction, making it an ideal choice for lubrication and an ideal coating for the inner layer of easy-to-clean cookware and water pipes. PTFE features atmospheric aging resistance, non-flammability, resistance to acids and alkalis, insolubility in strong acids, strong alkalis, and organic solvents (including magic acid, i.e., fluorosulfonic acid), and oxidation resistance. It is commonly used in corrosion-resistant pipes, containers, pumps, valves, as well as in the manufacturing of radars, high-frequency communication equipment, and radio equipment. In the water treatment, it is suitable for concentrated hydrochloric acid, concentrated sulfuric acid, and other high-acidity or alkaline solution treatment.

The material varies, so as these dosing pump costs. We shall choose different dosing pumps according to the water quality. PP and PVC dosing pumps are commonly seen in daily life sewage treatment. In swimming pool water treatment, PP dosing pumps are generally highly recommended, while PTFE dosing pumps are selected for high concentration of acid and alkali wok organic solvents. Choosing the right metering pump is beneficial to the construction cost and treatment effect of water treatment.