Flat tubing is used by market gardeners and other commercial growers for main supply lines, submains, headers and manifolds. The advantages of flat tubing are:

• Easy to ship and store
• Inexpensive compared to rigid tubing
• Lightweight and easy to move to a new location
• Adapter fittings are available that attach lateral tubing directly to flat tubing

Pressure

There are two types of flat tubing, high-pressure and low-pressure. High-pressure is used for supply lines from the pump to the field with pressures up to 80 psi.

Low-pressure flat tubing is used for manifolds, headers and submains where the pressure has been regulated and reduced to 21 psi or less. The thin wall thickness of low-pressure flat tubing limits the working pressure but allows the easy use of plug-in adapters.

High-pressure Supply Lines

The supply line tubing from the pump or water source to the field must be durable and rated for high pressure. Our 2" diameter T8 flat tubing is rated for 80 psi and is shipped in a compact coil that is easy to deploy, re-coil or store. The maximum flow rate for 2" tubing is 40 gallons per minute (with a 1.4 psi pressure loss per 100').

You can use standard 2" insert fittings from your local plumbing shop to join lengths or add an elbow, a tee or a reducer. Gear clamps are required.

Flat supply line must be left on the surface and is especially useful if the drip irrigation system will be moved after a few years. The tubing can be bent in a very long shallow curve but will tend to kink or straighten under pressure if the curve is too tight. Elbows and tees should be used to change direction.

A large filter is installed at either the start or end of the main supply line. A pressure regulator is usually installed at the end. That way, full pressure is maintained right up to the boundary of the drip irrigation area.

2" flat tubing is used as a main supply line
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Various attachments for a flat tubing manifold
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Low-pressure Manifolds

The photo to the left shows three ways to attach tubing to a manifold made of low-pressure flat tubing. Our T6 tubing is 1-1/2" in diameter and rated for 21 psi. The maximum flow rate for 1-1/2" tubing is 26 gallons per minute (with a 2 psi pressure loss per 100').

The wall thickness of low-pressure flat tubing is thin enough that it is easy to cut a .400" hole and attach an adapter for thinwall dripline. It's simple - cut the hole using a TL5 tool, push the adapter in place and attach the dripline. The manifold is quick to build and eliminates the extra costs of rigid tees and reducers. If you change the position of an adapter, OE18 hole plugs are available to blank off the old hole. Or use an FB22 Adapter with a built-in valve that may be closed.

If your rows are short and use less than 1-1/2 gallon per minute, you can use a FB31 Adapter. This adapter is similar to the FB23 but it has a small 1/4" barb instead of the large .400" barb of the FB23. Use a standard punch to install the FB31.

If you wish to attach 1/2" tubing to a flat tubing manifold, there are two ways. You can use an insert tee (FB24) and an adapter (FB20) as shown in the photo above. Gear clamps (OE21) are required for the both insert sides of the tee.

Another simpler way to attach 1/2" tubing to a flat tubing manifold, as seen to the left, is to use an FB23 Adapter, a short 6" length of DL6 Thinwall dripline without a dripper, and then use an FB33 Adapter to attach the 1/2" tubing to the short length of dripline.

Cutting the holes

Cutting the holes in 1-1/2" low-pressure flat tubing for adapters is easy. Cut the holes in the folded edge of the flat tubing so that all holes line up in the same plane and direction. As seen in the photo below, the TL4 tool is designed to be used with an FB23 Adapter. Cut the hole and push the Adapter in place in one operation.

Plugs are available to close extra holes in the T6 Flat Tubing