Mainline Tubing Buying Guide
How do you know which mainline tubing is best for you?
There are several options for tubing in irrigation systems; these options include PVC, Blu Lock, IPS, or LDPE. The most common tubing used for drip systems is low-density poly mainline (LDPE).
The PVC pipe can handle high, constant pressure which makes it ideal for sprinkler irrigation systems. The PVC pipe is buried underground and used to move water from a water source to different locations throughout the system. The PVC pipe is classified as "schedule" or "class". Scheduled PVC is categorized by wall thickness. A schedule 40 PVC pipe will have the same wall thickness for every size from 1/2" to 10" or bigger. The pressure rating for schedule PVC will change with pipe size. We carry PVC Schedule 40 PVC fittings in 1/2", 3/4", and 1" sizes. Additional sizes can be specially ordered. PVC pipes come in 10ft and 20ft length, and the best place to buy them is your neighborhood hardware store.
"Class" PVC pipe is a different labeling system. Rather than categorization by wall thickness, the "class" designation rates the internal pressure that the pipe can take instead. A "class 200" PVC pipe can take 200 psi, no matter what the diameter of pipe is. If you need to move a large amount of water a long distance at a medium pressure, "class" PVC might be the best option for you. If you have high pressure and a low volume of water, then "schedule" PVC could be the better choice.
Blu lock tubing is a type of HDPE (high-density polyethylene) that can be used in place of PVC pipe. Blu Lock tubing offers extreme flexibility and does not require any glue or clamps. The manufacturer of Blu Lock tubing has created a line of reusable compression lock fittings specifically for their tubing which can be installed easily by hand. The benefit of Blu Lock tubing is the increased flexibility and ease of installation. This tubing can handle a higher pressure than our traditional low-density poly tubing. Blu lock tubing must be placed after a shut-off valve or timer as it cannot handle constant pressure. We carry Blu Lock tubing in 1/2", 3/4", and 1" sizes. Additional sizes can be specially ordered.
IPS tubing is another type of HDPE tubing that can be used in place of PVC pipe for areas that require more flexibility. IPS tubing must be placed after a valve or timer. The IPS tubing will use standard PVC fittings and will require PVC glue to create a seal. We carry IPS tubing in 1/2" and 3/4" sizes. Additional sizes can be in special order.
DripWorks has several size options of low-density (LDPE) tubing to fit your irrigation needs.
Use this chart as a guide to begin narrowing down your search for the right size mainline:
|
Tubing Size (ID-OD) |
Maximum Flow Rate |
Pressure Loss per 100' |
Maximum row length |
Maximum PSI |
|
1/4" 0.17" ID-0.25" OD |
0.5 GPM or 30 GPH |
N/A |
30' |
30 PSI |
|
1/2" 0.60" ID-0.70" OD |
4 GPM or 240 GPH |
Approximately 7 PSI |
Roughly 400' |
50 PSI |
|
3/4" 0.83" ID-0.94" OD |
8 GPM or 480 GPH |
3-4 PSI |
Roughly 800' |
50 PSI |
Let's go over this information in more depth.
First, every manufacturer of poly tubing has a different standard for sizing their tubing. Unlike PVC, there is no industry standard for poly tubing sizing. You will see that our 1/2" tubing is technically closer to a true 3/4" and the 3/4" is closer to a true 1". It is very important when buying poly tubing and fittings that you pay close attention to the ID and OD listed to ensure your tubing and fittings are compatible. We suggest you purchase your fittings and tubing from the same source. Poly tubing is a great choice for a drip irrigation system because it offers more flexibility than PVC pipe and poly tubing does not require glue, just some simple fittings.
Here is a guide to help you determine which size tubing you currently have:
The first step to selecting the right size mainline tubing for your system is to check your available flow rate. To check your flow rate, use our flow calculator online and follow the instructions in our video.
You will want to pick a tubing that gives you access to as much of your flow rate as possible, without being too large. If you have 5 GPM available from your source, your mainline choice would be between 1/2" polyethylene and 3/4" polyethylene. The 1/2" poly tubing has a flow capacity of 4 GPM which is close to the available flow rate from your water source, which makes it an ideal choice. The 3/4" poly tubing has a flow capacity of 8 GPM, which is higher than the 1/2" poly tubing.
The other factor that will help you determine what size tubing is right for your system is the amount of flow your system will require. For instance, if you are only watering three small garden beds but have 8 GPM available from your water source, what mainline size is going to be the best option? Our small garden bed kit, which can water three garden beds, uses approximately 1.3 GPM, so the 1/2" mainline is more than enough to supply those garden beds with water. Using the larger 3/4" mainline tubing because your available flow rate is higher, would increase the cost of your irrigation system and not offer much benefit.
The small tubing that is commonly referred to as "spaghetti tubing" comes in either a poly or vinyl option. The vinyl tubing has a slightly thicker wall than the poly tubing, but they will both use the same 1/4" fittings. While both the poly and vinyl options are pliable and can be circled or snaked throughout your plants, the vinyl is a much softer tubing. This is great when you need something extremely flexible, but it does have its downside. Vinyl tubing does not handle heat well. As the tubing gets warmer, it gets softer. If you live in a warm climate area where it often reaches 80 degrees during your growing season, vinyl tubing is not going to be your best choice as fittings could become loose and pop-off when the tubing becomes soft in warm weather. You will want to stick with the slightly more rigid 1/4" poly tubing for a worry-free system.
Choosing the mainline size should be easy once you know your flow rate and flow rate usage requirements of your drip system. At DripWorks, we carry the best products from some of the biggest names in the irrigation industry, such as Netafim, Rain Bird, and Irritec, to ensure that the products you purchase from us will be of the highest quality.