What Is a PVC Flange?
A flange is a type of pipe joint that is used to connect pipes or to close the end of pipes and is characterized by its flange-like shape.
PVC is one of the five most inexpensive general-purpose resins, along with polypropylene (PP), polystyrene (PS), and polyethylene (PE), and is in high demand.
Uses of PVC Flanges
Uses of PVC flanges include piping flanges for chemical plants, semiconductor-related plants, and seawater piping flanges. This is because the excellent corrosion resistance of this material prevents it from being corroded by acidic or alkaline chemicals or seawater.
Polyvinyl chloride (PVC) is available in both hard and soft types, and especially hard PVC is widely used for building materials such as flange applications and piping materials.
Furthermore, the adhesive properties of PVC solvent-based adhesives, etc., are excellent, making them suitable for TS flange applications, in which adhesive materials are used to join two flange-like shapes together.
Principle of PVC Flanges
Polyvinyl chloride (PVC) is synthesized by the addition polymerization of vinyl chloride monomer (CH2=CHCl) and can be hard or soft depending on the amount of plasticizer added. In the case of PVC flanges, the average degree of polymerization of polyvinyl chloride (PVC) is about 600 to 1000.
In addition to the hardness of the material, integral injection molding, a type of plastic processing, is often used as a means of improving flange strength. The one-piece injection molding is a molding method in which molten resin material is poured into a mold and solidified. PVC flanges made by this molding method are very robust in terms of strength because they are one-piece and are resistant to cracks caused by weld formation.
In addition to the aforementioned adhesive-type TS flanges, there are also custom-made PVC flanges for food processing machinery that have improved sealing effects by grooving the inside of the flange to accommodate an O-ring, This takes advantage of the excellent degree of sealing, lightweight, and relatively easy special processing that are unique to resin flanges.
On the other hand, the disadvantage of polyvinyl chloride (PVC) is its relatively low heat resistance, with a heat resistance temperature of 60 to 80°C and a melting point of 85 to 210°C. In addition, its impact resistance is greatly reduced, especially in low-temperature environments.