If you purchased your tubing or drip tape from Drip Depot, then you should simply order fittings that match the size listed in the description of the tape or the tubing. For example, if you ordered 1/4" poly tubing, then any of our 1/4" fittings are guaranteed to fit. This holds true for all tubing, tape and fittings sold by Drip Depot.
What if you purchased your tubing elsewhere? It can be difficult to find compatible fittings, since there are no industry standards regarding drip irrigation tubing sizes. For example, manufacturers may list their tubing size as ½”, but it is really the inside diameter (ID) and outside diameter (OD) that will help you in sourcing the correctly sized fittings. We have an in-depth article about adding to existing drip irrigation systems and sourcing proper fittings that can be found here: Tips for adding to an existing drip irrigation system
How to Choose a Fitting Type
For ¼” tubing, the choice is easy because there is only one type available and that is barbed. For other sizes of tubing, there may be up to 3 choices of fitting styles. Those three styles are known as Barbed, Compression and Perma-Loc. Each has its own advantages and disadvantages, which will be explained below.
Barbed fittings are economical and are easy to use. They are available for use with ¼”, ½” & ¾” tubing sizes. Simply push the fitting into an open end of tubing. Make sure to push the tubing as far over the fitting as possible. That's it! However, if you have ever tried to push a barbed fitting into cold tubing, you know it can be struggle. If you are going to use barbed fittings, we highly recommend that you put some warm water in a cup (do not use boiling water — it could damage the tubing and burn you) and dunk the end of the tubing in it for approximately 10 seconds before attempting to push in a barbed fitting. The warm water temporarily softens the tubing and makes fitting insertion much easier. Alternatively, if you are working with ¼” fittings and want a really slick way of inserting them, check out our ¼” fitting insertion tool.
So what are the negatives to using barbed fittings? As we’ve mentioned, they can be difficult to push into tubing. Another drawback is that they are not reusable. This means that once you insert them, they cannot be removed and placed elsewhere. If you need to reconfigure your drip system from year to year, you would not want to use barbed fittings.
Compression fittings are very popular with contractors or other people doing large-scale projects due to the low cost of the fittings. However, compression fittings are the most difficult fittings to insert into tubing. Installing a compression fitting can be frustrating, and it may take many attempts to attach the tubing to the fitting. We have two solutions to make compression fitting insertion easier: 1) heat the end of the tubing with warm water or 2) mix some soap with warm water and cover the end of the tubing. In addition to being hard to install, compression fittings are not reusable. Once inserted into tubing, these fittings cannot be removed.
Note: Compression fittings are available only for ½” tubing
Perma-Loc fittings are the Cadillac of drip irrigation fittings. They are easy to use, extremely durable and reusable. Due to the extreme durability and reusability of Perma-Loc fittings, we highly recommend them for all projects. In fact, these are the fittings that we include in each Drip Depot kit. The fitting has a locking nut that rotates over top of the tubing, locking the tubing into place once the tubing has been pushed over the tapered barb. The same nut can be rotated backward off the tubing allowing the tubing to be pulled off the barb and the fitting to be reused wherever needed. This is a big advantage over barbed and compression fittings. The only negative to using a Perma-Loc fitting is the price. They are more expensive than the other fitting types, but ease of use and reusability make the price difference worth it.
Perma-Loc tubing fittings are available for use with drip irrigation poly tubing in the following sizes: ½”, ¾” and 1". We also have Drip Tape Perma-Loc fittings that work with ⅝” and ⅞” drip tape. All of our Perma-Loc fittings are manufactured in the USA.