The Christmas Tree Farm, Duncan, OK - Drip Irrigation Terms and Definitions

Drip irrigation uses a few uniqe terms and and many technical terms which may not be familiar to everyone. We have included some of these terms below with simple explainations and definitions. We hope this will get you familiar with the lanquage.

Barb
A type of fitting end with a tapered end and a raised edge to grip the tube or hose. A tube or fitting is pushed onto the barb to make a connection. At low pressure, friction is used to hold the tube or hose on the barb. At higher pressure, a hose clamp may be needed to keep the tube or hose on the barb.

Compression Fitting
A type of connection which uses an internal barb or sharp edge to compress the tube that is attached. Increasing the internal pressure of the tube forces the fitting to grip tighter on the tube. This is a fast assembly method not intended for disassembly. However, applying extra force can remove the tube if needed. The tube will be damaged but the damaged end can be cut off.

Coupler
A type of fitting with two connections. The two connections are inline with each other. This fitting is used to extend or repair damage in a run of pipe or tube. Diameter. The distance from one side through the center to the other side of a circle .

Drip Irrigation
Drip Irrigation is the broad term used to describe all of the techniques used to apply a small amount of water directly at the point of use. Drip irrigation was originally developed in desert areas to conserve water. The advantage over sprinklers is the reduction of water wasted to evaporation and applied to areas away from the desired plants. On a windy day with low humidity, most of a sprinkler system's water may evaporate. Also called micro irrigation.

Drip Tape
Drip tape is a special type of tubing used for drip irrigation of a row. This tape is made in several types but typically will have a series of openings spaced 1 to 2 feet apart which will release water slowly and provide irrigation of a continuous strip. Drip tape is used for garden rows, tree seedlings and large scale commercial field irrigation as an alternative to overhead sprinkler systems. Additives are used to keep the tube usable over a range of temperatures and to prevent deterioration in the sun.

Drip Tube
Drip tube is the polyethylene tubing used for headers and supply lines for a drip irrigation tube. This special tube is manufactured with thin wall to keep cost down. The pressure rating is suitable for drip irrigation but may not by suitable for a high pressure (city or well) system. Additives are used to keep the tube usable over a range of temperatures and to prevent deterioration in the sun.

Ell
A type of fitting with two connections. The two connections are 90 degrees to each other. This fitting is used to turn a corner in a run of pipe or tube. Also called an elbow.

Emitter
These are the devices which allow the water to drip slowly from the supply tube to the point of irrigation. Also called drippers. See NPC and PC.

Garden Hose Thread
This is the standard thread used for all common garden hose connections. It is available in male and female versions. This is also the thread commonly used outside faucet and frost proof water hydrants.

Goof Plug
A tapered plug with a barbed end used to plug a hole in a poly tube. These are used if an emitter is placed in the wrong spot and must be moved. It can also be used to plug some accidental holes if they are small and the edges are smooth. The typical goof plug has two size plugs on the same part. Some goof plugs have a single barb and a smooth cap which makes the goof plug less noticeable.

GPH
Gallons per Hour, a measure of flow rate. This is used as the measure of the amount of fluid (in drip irrigation this is usually water) flowing through a tube or emitter in one hour.

GPM
Gallons per Minute, a measure of flow rate. This is used as the measure of the amount of fluid (in drip irrigation this is usually water) flowing through a tube or emitter in one minute.

Header
A header is the main supply line from which smaller branch lines are supplied. It may be larger to allow for the greater water flow required to supply several branch lines. Pressure drop is the main design consideration.

Nominal
Some tube and pipe is called a fractional nominal size but does not actually measure this exact size. This is not cheating but it can be confusing. Typically the actual pipe measurement is larger than the nominal pipe size. Charts are available if you just have to know about pipe sizes.

NPC
Non Pressure Compensated. This term is used to describe a class of emitters which vary their flow rate with varying pressure applied to the inlet of the emitter. These emitters are usually cheaper than Pressure Compensated emitters.

PC
Pressure Compensated. This term is used to describe a class of emitters which can maintain their flow rate constant over a range of pressure applied to the inlet of the emitter. This is a good feature because it will water all of a long row with the same amount of water and not be effected by the pressure drop in the supply tube. They are also used when the area to be irrigated has a large rise or fall in elevation. These emitters usually cost more than Non Pressure Compensated emitters.

Poly or polyethylene
A type of plastic used to make drip tubing and some fittings. It is strong, flexible and smooth. Additives are added to prevent deterioration in the sun.

Pot Dripper
A special type of emitter used for watering a pot or container of plants. The pot dripper has a small tube (sometimes called spaghetti tube) to supply the emitter water from the supply line. A pot dripper may have a stake or weight to keep the emitter in the container.

Pressure Drop
The decrease in pressure from one point in a pipe or tube to another down stream. This is usually the result of friction of the water against the tube. High flow rates in small tubes give large pressure drop. Low flow rates in large tubes give low pressure drop.

Pressure Regulator
A pressure regulator is used to reduce high water pressure to the range suitable for drip irrigation. They are available in various flow ratings and pressure settings. They need to be matched to the drip irrigation system requirements. Some have pipe threads and others have garden hose thread ends.

PSI
Pounds per square inch, a measure of pressure. Technically this is a force per unit of area.

Tee
A type of fitting with three connections. Two connections are inline (these are called the 'run' side) and another connection 90 degrees to the first two. The third connection on the side is called the 'branch' connection. This fitting is used to branch from a run of pipe or tube.

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Drip Irrigation Terms and Definitions - The Christmas Tree Farm
Phone: 580 - 467 - 0104