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Tips for Adding To An Existing Drip Irrigation System

MARCH 5, 2014

If you already have a drip irrigation system and you are new to our website, you may be wondering, “Are Drip Depot products compatible with my current drip irrigation system?" That’s a great question. There is little variance in dripper barb sizes.  However, there are no industry standards regarding drip irrigation tubing. Which makes purchasing compatible fittings the most problematic aspect when adding to an existing drip irrigation system.

How do find compatible fittings? To answer that question you first need to know the inside diameter (ID) and outside diameter (OD) of your tubing. Also knowing the brand and size of your tubing, will ensure that you get the right fittings each time and have less hassle when it comes time to install them and expand your current system.

How to Find the I.D. and O.D. of Existing Tubing

Usually you will find these measurements marked somewhere along the tubing exterior or on a tag attached to the tubing. Many tubing manufacturers have their own methods of marking the tubing, you should be able to locate the markings and know what size of tubing you have.

If you cannot locate the markings on your tubing, be sure to correctly measure both the internal diameter and the external diameter before placing an order.  Knowing the correct size of your existing tubing when ordering new fittings will save you time and money and will allow you to add to your existing system with ease.

Why are there so many different 1/2" poly tubing sizes? 

1/2" tubing is the most popular and most manufactured drip irrigation tubing size. There is an excellent chance that your current system utilizes 1/2” tubing.  However, not all tubing manufacturers manufacture their 1/2” tubing to the same specifications as another manufacturer, hence there are no industry standards within the drip irrigation industry.   

Below is a handy table that offers you some insight into the most popular drip irrigation tubing manufacturers and which Drip Depot fittings will work with each brand and size of 1/2” tubing. If you know the brand, size, and both the inside diameter (ID) and outside diameter (OD) of your current tubing this chart will help you find compatible fittings that will allow you to expand your existing drip irrigation system.  

1/4” Microtubing

Right behind 1/2” tubing in popularity is 1/4” tubing.  1/4” tubing is also referred to as micro tubing and is often used to run drippers to plants that are located away from mainline tubing.

With 1/4" tubing there is not as much variance in size as there is with 1/2" tubing.  However, the key to purchasing compatible fittings is to know whether your 1/4" tubing has an inside diameter (ID) of .250" or an outside diameter (OD) of .250". Tubing with either measurement are both technically 1/4".  However, our barbed 1/4” fittings are compatible with 1/4” tubing that has an inside diameter (ID) of .175" and an outside diameter (OD) of .250".  If your 1/4" has an inside diameter (ID) of .250" then our fittings will be too small and thus not compatible. 

Below is a handy table that offers you some insight into the most popular drip irrigation microtubing manufacturers and which Drip Depot fittings will work with each brand and size of 1/4” tubing. Again, to properly use the chart you need to know the brand, size, and both the inside diameter (ID) and outside diameter (OD) of your 1/4" tubing. 

1/4" Tubing ManufacturerTubing Specifications Compatible Drip Depot Fittings
1/4" - O.D. .250" x I.D. .175"
1/4" - O.D. .250" x I.D. .175"
1/4" - O.D. .250" x I.D. .175"
1/4" - O.D. .250" x I.D. .175"
1/4" - O.D. .250" x I.D. .175"
1/4" - O.D. .250" x I.D. .175"

What about 3/4” and 1" Poly Tubing?

Other tubing sizes like and ¾” and 1” see little variance in size compatibility. 1” tubing is actually standardized throughout the industry.  So we can guarantee that our 1” fittings will work with your tubing and vice versa.  

Recommended Compatible Fittings:  3/4" Prema-Loc Fittings and 1" Perma-Loc Fittings

    Drip Irrigation Expert Mike

    Written by Mike Ricker | Mike Ricker is always looking for ways to make drip irrigation easier for everyone.  If you found this article useful or have a great tip please pass it on to Mike at: