What is commonly used to seal joints in plumbing systems?

Sealing joints in plumbing systems is essential to prevent leaks and ensure the integrity of the system. Each of the options listed serves a specific purpose when it comes to sealing and securing joints.

Sealant tape, often referred to as Teflon tape, is widely used to wrap around threaded joints to provide a watertight seal. It fills in the small gaps at the threads, preventing water from leaking out.

Thread sealant, or pipe dope, is a paste that is applied to the threads of pipes to create a seal. It provides additional sealing capabilities on threaded joints, particularly when using materials that may not tightly fit together when merely screwed.

PVC glue, or solvent cement, is specifically used for making permanent joints with PVC pipes. It chemically bonds the PVC surfaces together, forming a robust, watertight seal suitable for the intended use of PVC plumbing.

Since all these items are valid choices for sealing various types of joints in plumbing systems—whether they are threaded connections, plastic pipe joints, or otherwise—it's clear that each option has its application. Therefore, the correct response encompasses all of these methods as viable solutions for joint sealing in plumbing.