How are PVC casing strings joined?

• A. Welded joints with steel.
• B. Solvent cement or threaded joints.
• C. Adhesive tape only.
• D. Bolted with nuts.

Answer: (B)

PVC casing strings are joined either with solvent cement to chemically fuse the ends or with threaded connections that screw the sections together. Solvent cement works by softening the PVC surface so two pieces fuse into a single, watertight joint as the cement cures—this is common for continuous, leak‑free borehole casings. Threaded joints provide a mechanical connection that can be disassembled if needed, using appropriate thread sealant or tape to prevent leaks.

Welding joints with steel isn’t suitable because PVC is a plastic and won’t form a reliable bond with steel. Adhesive tape would not provide the long-term strength or watertight seal required in a borehole, and bolted with nuts isn’t a standard method for joining PVC casing.