When it comes to sealing threaded pipe connections in water applications, there are several types of tape and sealants available. The choice of the best tape depends on factors such as the type of pipes and fittings, water pressure, temperature, and specific requirements of the application. Here are some common types of tape and sealants used for sealing threaded pipe connections in water applications:

1. PTFE (Teflon) Tape: PTFE tape, also known as Teflon tape, is a popular choice for sealing threaded pipe connections in water applications. It is effective at creating a watertight seal and is resistant to water, chemicals, and corrosion. PTFE tape is suitable for use with most metal and plastic pipes and fittings and is widely available.
2. Thread Sealant Compound: Thread sealant compounds, also known as pipe dope or pipe joint compound, are liquid or paste-like substances applied to the threads of pipe fittings before assembly. These compounds provide a reliable seal against leaks in water applications. They come in different formulations for various types of pipes and applications and may offer advantages such as resistance to high temperatures and pressures.
3. Pipe Thread Sealant Tape: Unlike PTFE tape, which is made of PTFE material, pipe thread sealant tape is made of different materials such as polyethylene or PVC. This type of tape is specifically designed for sealing threaded pipe connections and is suitable for use with water and other fluids. Pipe thread sealant tape is often thicker and denser than PTFE tape, providing enhanced sealing properties in some applications.
4. Anaerobic Thread Sealant: Anaerobic thread sealants are liquid sealants that cure in the absence of air (anaerobic conditions) to form a solid seal. These sealants are effective for sealing threaded pipe connections in water applications and offer advantages such as high temperature and chemical resistance.
5. Pipe Thread Sealant Cord: Sealant cords are pre-formed strings of sealing material designed to be wrapped around pipe threads before assembly. These cords provide a reliable seal against leaks in water applications and are easy to use.

The best tape or sealant to use in water applications depends on factors such as the type of pipes and fittings, operating conditions, and specific requirements of the application. It’s essential to select a tape or sealant that is compatible with the materials and conditions present in the plumbing system and to follow the manufacturer’s instructions for proper application. If unsure, consulting with a plumbing professional can help determine the best sealing solution for your specific needs.