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Tubular Drainage Products

Tubular products consist of the traps and other pipes and fittings found under sinks that connect them to the drainage lines.

Tubular products are manufactured in a sizing standard that is neither compatible with IPS pipe nor with CTS tubing. These products are made in tube sizes, but the threads used on them are incompatible with other products. They are adjustable, easily removed for repairs or cleaning, and can be assembled without making precise measurements and cuts.

Every open drain requires a trap be installed below it to prevent sewer gas from escaping into the house. This trap is always full of water. The specific configuration of the trap will depend on the type of sink under which it's installed and the location of the drainage pipe to which it connects.

They are connected by slip-joints that do not require any special tools for assembly. One end of each section "slips" into the next. Plain male ends slip into milled sockets (female ends) that are threaded on the outside. A slip joint nut is tightened onto the thread of the milled socket. As it is tightened, it compresses a soft plastic tapered gasket, (or ferrule) which squeezes firmly against the gasket or packing and forms a water-tight seal. These joints are not considered to be permanent connections, so they cannot be concealed behind walls, and they are prohibited on the sewer side of the trap.

These connections begin at the sink drain; in kitchen sinks, this starts with a basket strainer. Chrome basket strainers are the most popular because they will not tarnish with proper care. Metal-bodied basket strainers with special (non chrome) finishes are sometimes chosen to match decorative faucets, but they are generally not preferred because they tend to corrode under harsh sink conditions as in disposing of acidic foods like tomatoes or citrus fruit. The underside of the basket strainer is threaded to accept an extension tube that leads to the trap.

In most other types of sinks, there is no basket strainer, but merely a metal flange that fits Into the drain opening. This flange is part of an assembly that includes a similar extension tube that feeds the trap. It includes gaskets and fittings that attach to the sink bowl to hold it in place. This assembly may include parts necessary to activate a pop-up drain assembly or just provide for a drain stopper.

Years ago, these products were made of unpolished brass. As consumers became more attentive to the appearance of the fixtures in their homes, chrome-plated products became more popular. In recent years, PVC has made inroads into this field, especially whenever they are concealed inside cabinets. PVC has the advantage of being chemically inert and will not corrode over time. Polished Chrome is sometimes called "Satin Nickel".

Tubular chrome and PVC are sold in two basic sizes, 1 ¼" for lavatories and 1 ½" for kitchen sinks. They are also available in 2" size for bathtubs. Older model footed tubs used to use1 3/8". Those can be adapted to the current standard by simply using a thicker washer or by using an adapter.

Chrome-plated tubular brass is sold in two gauges, standard 20 gauge for residential use and heavier 17 gauge for commercial use. The nominal size is measured by its outside diameter, while the nominal size in PVC pipe is measured by its inside diameter. This means that the slip-joint drain fittings will slide inside the drain pipe, and desanco fittings are used where the tubular drain pipe connects to IPS pipe or CTS tubing.

Most new houses use a horizontal drain line under the sink that runs into the wall. Horizontal drains are popular because they do not need holes drilled in the bottom of the sink base cabinet. If there is a second basin, that basin will attach to a "T" junction fitting, which flows into the "S" trap, which in turn leads into the building drain.

The "S" trap fit includes the two-component trap and a long section of 1-1/2" PVC tube. The purpose of the short straight piece is to connect to the threaded adapter on the existing drain pipe. The trap can easily be positioned to fold back on itself, allowing it to fit in a tight space, or to connect two vertical pipes that are fairly close together.

There are a wide variety of fittings available to accommodate nearly any situation one might Encounter. See us for your special needs. Below are shown a selection of a few of the other popular tubular fittings in chrome and PVC

The long rod is the connecting link for the drain stopper. That whole assembly is inserted into the overflow tube. Adjustment of the length of the linkage is important, if it's too short, the stopper won't hold water. If it's too long, the water won't drain fast enough, and the drain may tend to clog.

See Also:

Other:
    ASTM Reference Library (material and manufacturing specifications)

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