SCH8O/DIN UPVC/CPVC Ⅰ Union

Differences between UPVC and CPVC Type I Unions: Material properties and application scenarios

UPVC (unplasticized polyvinyl chloride) and CPVC (chlorinated polyvinyl chloride) are two thermoplastic materials widely used in industrial piping systems. As a key connector, the material selection of Type I Union directly affects the safety, corrosion resistance and service life of the system. This article will analyze the core differences and selection recommendations of the two based on material properties and combined with different industry application scenarios.

1. Comparison of material properties

(1) UPVC (Unplasticized Polyvinyl Chloride)
Temperature resistance: The working temperature is usually ≤60℃, and the short-term temperature resistance can reach 80℃. It is suitable for normal temperature or low temperature medium transportation.
Corrosion resistance: It has good tolerance to chemicals such as acids, alkalis, and salts, but is not resistant to some organic solvents (such as ketones and aromatic hydrocarbons).
Mechanical strength: It has high rigidity, but its brittleness increases under low temperature conditions and its impact resistance is weak.

(2) CPVC (Chlorinated Polyvinyl Chloride)
Temperature resistance: The working temperature can reach 93℃ (long term) ~ 110℃ (short term), suitable for high temperature media.
Corrosion resistance: Further optimized on the basis of UPVC, with stronger acid and alkali resistance, especially suitable for high concentration chemical environment.
Mechanical properties: Maintain high strength at high temperature, and better creep resistance than UPVC.

2. Applicable scenarios and industry analysis

(1) Typical applications of UPVC Type I joints
Drinking Water: Meets hygiene standards, no plasticizer precipitation, suitable for municipal water supply and household pipe systems.
Industrial Water Treatment: Used for cooling water and pure water transportation, resistant to chloride ion corrosion.
Photovoltaic: Transport low-corrosive fluids in solar panel cooling systems.
Electronic Semiconductor: Ultrapure water transportation pipeline to avoid metal ion contamination.

(2) Typical applications of CPVC Type I unions
Metallurgy: Resistant to high temperature pickling liquid and electroplating wastewater, suitable for corrosive medium transportation in smelters.
Nuclear Power: Auxiliary cooling system, resistant to radiation and high temperature softening.
Medicine: High temperature sterilization process (such as injection water system), in line with FDA certification requirements.
Industrial Wastewater: Treating wastewater containing strong acid, strong alkali or organic solvent, with better long-term stability.

3. Key factors for selection

Temperature: CPVC must be selected for high temperature scenarios (>60℃), and UPVC can be selected for room temperature or low temperature to reduce costs.
Media corrosiveness: UPVC is suitable for general acid and alkali environments, while CPVC performs better in strong oxidants (such as concentrated sulfuric acid and sodium hypochlorite).
Industry specifications: Nuclear energy, medicine and other fields must comply with specific certifications (such as NSF, ASTM), and CPVC is usually easier to meet high standards.