SCH8O/DIN UPVC/CPVC Cross

Key connections in industrial piping systems: Installation and sealing technology of UPVC/CPVC Cross joints

In industrial piping systems, UPVC (unplasticized polyvinyl chloride) and CPVC (chlorinated polyvinyl chloride) cross joints (Cross) are key connection components and are widely used in high-pressure, corrosive media and complex fluid transportation scenarios. Different industries have specific requirements for material properties, sealing technology and installation specifications. The following are application analysis and technical points for various industries:

1. Safe Drinking Water
Material selection: UPVC is widely used in drinking water transportation pipelines due to its non-toxicity, chlorine resistance and low cost.
Sealing technology: Use solvent-based adhesives or rubber seals to ensure no leakage and comply with NSF/ANSI 61 drinking water safety standards.
Installation points: Avoid over-tightening to prevent UPVC brittle cracking, and use support frames to reduce vibration effects.

2. Metallurgy
Corrosion resistance requirements: CPVC cross joints are suitable for acidic (such as sulfuric acid, hydrochloric acid) or alkaline coolant delivery systems.
High temperature adaptability: CPVC has a temperature resistance of more than 90°C and can be used for high-temperature flue gas purification or cooling water pipelines.
Sealing method: flange connection + PTFE gasket to prevent leakage of highly corrosive media.

3. Photovoltaic industry
Application scenarios: high-purity water, chemical etching solution (such as hydrofluoric acid) delivery pipelines.
Material requirements: CPVC has better hydrofluoric acid resistance than UPVC, but long-term UV aging resistance needs to be verified (when installed outdoors).
Installation specifications: Use electric fusion connection or hot fusion butt connection to ensure no particle contamination (critical for wafer cleaning systems).

4. Nuclear power plant
Safety standards: UPVC/CPVC joints must meet ASME NQA-1 nuclear grade quality requirements for low-radioactive wastewater treatment.
Anti-seismic design: Add anti-seismic brackets to avoid loose joints caused by pipeline displacement.
Sealing redundancy: Double sealing (O-ring + adhesive) to prevent leakage risks.

5. Electronic Semiconductor
Ultra-high purity media: CPVC is used for ultrapure water (UPW) and chemical (such as IPA, ammonia) distribution systems.
Clean room compatibility: The inner wall of the joint needs to be polished (Ra≤0.8μm) to prevent particles from contaminating the process fluid.
Installation process: Use ISO 14644 standard clean installation, and silicone-containing sealing materials are prohibited.

6. Medicine
Sterility requirements: UPVC is used for water for injection (WFI) pipes and must comply with FDA 21 CFR and GMP standards.
Removable design: Sanitary clamp connection (Tri-Clamp) for easy cleaning and sterilization (such as CIP/SIP system).

7. Industrial Water Treatment
Chemical resistance: CPVC is suitable for RO membrane pretreatment (chlorine resistance, oxidant resistance), and UPVC is used for back-end drainage.
Leakage prevention measures: Socket joint + annular water stop to cope with high flow impact.

8. Industrial Wastewater
Corrosive wastewater: CPVC cross joints can withstand pH 2-12 and are suitable for electroplating and chemical wastewater pipelines.
Installation slope: Gravity flow systems must ensure a slope of 0.5%-1% to prevent sediment from clogging the cross joint.
Summary of general installation and sealing technology
Surface treatment: Deburr after cutting and clean the bonding surface with acetone (for UPVC/CPVC solvent connection).
Thermal expansion compensation: CPVC pipelines must be equipped with expansion joints every 3-5 meters to avoid stress cracking of the joints caused by temperature changes.
Pressure test: After installation, test the pressure at 1.5 times the working pressure and maintain the pressure for 30 minutes without leakage (refer to ASTM D1785).