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EspañolConnecting PVC pipes to a metal spigot (metal faucet or valve) is a common task in home plumbing repairs. Due to the different hardness and thermal expansion/contraction rates of plastic and metal, special care is needed during connection to prevent leaks or cracked fittings.
Content
◾ How to Connect PVC to a Metal Spigot
1. Choose the correct connection method: Male thread to female thread
Core principle: It is strongly recommended to use a PVC male threaded fitting (male end) screwed into a metal female threaded fitting (female end).
Reason: If done the other way around (metal male thread screwed into PVC female thread), the metal is too hard, and even slight tightening can easily crack the plastic joint, leading to leaks.
2. Prepare the thread sealant
Use PTFE tape (plumber's tape): Wrap several layers of PTFE tape around the male threads of the PVC fitting, following the direction of the threads. This fills the tiny gaps between the threads.
Apply pipe sealant (optional): For extra security, you can apply a thin layer of pipe sealant (also known as "pipe dope") over the PTFE tape. This provides both sealing and lubrication, making the tightening process smoother.
3. Hand-tighten and reinforce
Hand-tighten first: Align the prepared PVC fitting with the metal spigot's connection and gently screw it in by hand. Ensure the threads are aligned and not cross-threaded.
Reinforce appropriately: After hand-tightening as much as possible, use a wrench or pipe wrench to turn it one or two more turns.
Caution: Do not overtighten! Just tighten until it feels secure and doesn't leak. Overtightening is the main cause of damage to plastic fittings.
4. Connect the remaining PVC pipe
Clean and apply adhesive: On the other end of the PVC fitting (usually a smooth socket) and the PVC pipe to be connected, wipe with a cleaner first, then evenly apply PVC cement.
Insert and secure: Quickly insert the pipe into the fitting, rotate slightly to distribute the adhesive evenly, and hold for a few seconds until it is initially secured.
◾ Special circumstances: What if there are no threads?
If your metal spigot is a smooth metal pipe without threads, or if the space is too small to work with:
Use a universal rubber connector (with clamps): You can buy a special connector with a rubber sleeve in the middle and stainless steel metal clamps at both ends.
Installation method: Attach one end to the metal pipe and the other end to the PVC pipe, then tighten the clamps at both ends with a screwdriver. This method seals through the compression of the rubber, making it ideal for transitions between different materials and capable of absorbing some vibration.
