Flexible water supply tubing comes in four main types, with connections that are typically 1/4-, 3/8-, or 1/2-inch to match various water supply pipe and fixture tailpiece sizes. Before buying, it’s always a good idea to have a look under the sink or behind the fixture to see what length of flex tube you will need and the size of the end fittings required. Often, there is even a tag on the old flex tube that indicates the length and size of each end nut so you don’t have to measure or guess. Below we break down the four types of flexible water supply tubes and the factors you should consider when choosing which is best for your connection needs. Strong and durable, PVC flex tubes are made of a PVC (polyvinyl chloride) outer core that is usually braided with nylon, and an inner core made of solid PVC. This type of flex tube is often the least expensive option. But although they are cheap, they are very flexible, offering amazing strength and ease of use. Keep in mind that PVC flex lines are not as corrosion-resistant when used in an exposed area—sunlight can weaken the material. They are suitable for hot and cold water and are a great, inexpensive option for faucet and toilet connections alike. These inexpensive PVC flex lines are not quite as durable and long-lasting as braided nylon or other types. Flexible water supply tubes made from braided nylon come with a reinforced braided outer layer and have a solid PVC inner core. They are usually white in color. This type of water supply tube is good for use with either hot or cold water supply lines. They can be used for most fixtures, including faucets, toilets, and more. Nylon flex tubes are very flexible, so they can be bought long and easily looped if necessary. They come in a variety of lengths, and the attachment nuts may even have winged levers that allow you to hand-tighten the nuts without the need for a wrench or pliers. Polymer-coated flex tubes also have a PVC inner core, but the outer material is made of polymer-coated fibers. These tubes look a lot like stainless steel braided lines, and, like the stainless steel lines, they resist corrosion very effectively. Also, like braided steel, they are a good option where a premium appearance is needed, such as the exposed locations under a toilet or pedestal sink. Unlike stainless steel tubing, however, polymer-coated tubes are very easy to bend and loop in situations where they are overly long, or when you need to make up for a big offset between connections. Another difference is that this type of flex tube is less expensive than braided steel. Like all the other flex lines, these are hot and cold water compatible, so they can be used for many applications. Stainless steel flex tubes are made of braided stainless steel surrounding an inner tube of PVC or nylon. The finish is a shiny metal with a textured, fabric-like look. The stainless steel on the outside is great in exposed areas, not only for appearance but also because the stainless steel protects the tubing from the environment by resisting corrosion. This type of supply tube is flexible but not quite as flexible as braided nylon, PVC, or polymer-coated tubes. Stainless steel braided flex tubes are appropriate for both hot and cold water lines. Braided stainless steel is usually the most expensive option for flexible supply tubes, but is also the most attractive and most durable. They also come in longer lengths that can be used for connecting dishwashers, refrigerator icemakers, and similar appliances, where you need a water supply tube with exceptional longevity. Consider the various performance characteristics of the four options before choosing the ideal type for your situation.
