Valve Buying Guide

Are you looking to buy irrigation valves but can’t quite decide on which ones? This guide provides a detailed breakdown of the different valve options to help you select the right one for your irrigation system.

What is an irrigation control valve?

An irrigation control valve is used to regulate the flow of water throughout your entire irrigation system, starting from the primary water source. An irrigation valve allows you to divide your irrigation system into multiple watering zones. An automated valve acts as the shut-off for the water source, with a signal from your irrigation controller.

Who needs an irrigation valve?

Anyone with a garden or landscape may need an irrigation valve. This will depend on the size of your garden or landscape, the type of irrigation you are using, and the available flow from your water source. Installing valves and creating irrigation zones provides you access to your available flow rate in each zone. Valves also allow you to accommodate different types of watering devices into zones to provide the most efficient use of these devices. For example, if you have pop-up sprinklers for your lawn and emitter tubing for your flower beds, these will need different watering durations.

How does a valve work?

The three main components of an irrigation control valve are the solenoid, the bonnet, and the diaphragm.

When the system is between watering cycles, water fills the bonnet chamber, putting pressure on the diaphragm and closing the valve. The first action to take place when a watering cycle is to begin, happens with the solenoid. The timer sends an electrical signal through the wires to the valve’s solenoid. This tells the valve to open or close. The solenoid coil then becomes an electromagnet and pulls the plunger up into the solenoid. This allows the water in the bonnet chamber to flow out of the valve via the outlet, which in turn decreases the pressure on the diaphragm. With the decreased pressure above the diaphragm from the water flowing out, the water entering the valve from the inlet can now rise high enough to push the diaphragm up, into the open position and allow continuous flow through the valve. At the end of the watering cycle, when the timer stops sending electricity to the solenoid, the plunger drops, and the water begins filling the bonnet chamber above the diaphragm once again. This forces the diaphragm back down and closes the valve.

How do you choose a valve?

When you are choosing an irrigation valve, the first thing you should consider is if you want an automated or a manual valve. You will also want to consider the flow rate requirement for each zone and your starting pressure.

Manual valves have a handle that is used to open and close the valve, starting and stopping the flow of water. A common manual valve example would be a ball valve. The spigot on your water faucet is also a type of manual valve. The downside to manual valves is the need for the user to turn the system on and off. If the homeowner is not always available to do this, the landscape or garden can suffer. There is also the risk that the valve may not get shut-off, leading to severe overwatering and increased water bills.

When choosing which automated valve to purchase, you will need to first determine what type of power source your controller is using. AC-powered controllers will only operate AC solenoid valves and battery powered controllers will only operate DC valves. DC-powered valves will have two different colored wires; most will have black and red wires, indicating positive and negative connections. Some are green and black. All AC-controlled valves will have two of the same-colored wires.

AC Valve options:

There are several different types of AC valves to choose from once you have decided this is the correct power source for you: Anti-siphon valves, globe valves, jar-top valves, and a standard flow-through valve.

Angle Globe

Jar-Top

Anti-Siphon

Globe

Galcon, Baccara, Irritrol, and Rainbird valves offer a globe version of AC valves. These valves come with a female pipe thread inlet and outlet. Flow control handles on the Galcon, Baccara, and Irritrol valves allow you to reduce the flow rate through the valve for lower flow systems. The minimum pressure required for the Baccara valve is 4.3 PSI, while the Galcon valve requires a minimum of 7 PSI.

Irritrol and Rainbird Anti-siphon valves are installed at least 6" above the highest point in your irrigation system. These valves have a built-in atmospheric vacuum breaker to eliminate back flow. By using one of these valves and installing it properly, you reduce the need for a separate backflow device and decrease your pressure loss through devices.

Irritrol Angled Globe valves are the perfect choice for dirty water sources. These valves can handle up to 220 PSI and have an internal bleed for flushing debris from the diaphragm. Angled globe valves are commonly installed underground and have the extra feature of an inlet on the base of the valve, creating a 90-degree angle between the inlet and outlet.

K-Rain and Hunter jar-top valves are the most accessible valves to clean. The top of the valve does not have any screws, you unscrew the top like you would a jar. This is where the valve gets its name. Neither of these valves have a flow control.

DC Valves:

The Baccara DC valve has the lowest pressure and flow rating of any DC valve. This valve has a 3/4" female pipe thread inlet and outlet. The minimum pressure required to open and close the valve is 4.3 PSI, with a maximum pressure rating of 145 PSI. With a minimum flow rate requirement of 0.5 GPM and a maximum flow rate of 22 GPM, the Baccara valve is an excellent option for a wide range of systems. This valve brand is identified as DC with one green wire and one black wire.

The DIG DC valve is identified with red and white wires. The valve has 3/4" female pipe thread inlet and outlets. This valve has a flow control handle, which gives the user the ability to reduce the flow rate through the valve as needed. Because of the flow control, the minimum flow rate on this valve can be turned down to 0.1 GPM, with a maximum flow rate of 28 GPM. While this valve has a slightly more extensive flow range than the Baccara valve, the minimum pressure required is higher. The operating pressure range for the DIG valve is 10-150 PSI.

The Galcon DC valve is identified by having one black and one red wire. The Galcon DC valve also comes with a flow control handle. DripWorks carries the DC valve in sizes ranging from 3/4" up to 2", with female pipe threads on the inlet and outlet on each size option. The operating pressure range for these valves is 10-150 PSI.

Manufacturer/Model	Power Source	Type	Features	Connection	Flow Rating	Pressure Range
Galcon: DC Latching Solenoid 24V AC Solenoid	DC AC	Globe Globe	Flow Control AC/DC have interchangeable solenoids for the 3/4" & 1" valve. Flow Control	3/4" FPT 1" FPT 1 1/2" FPT 2" FPT 3/4" FPT 1" FPT 1 1/2" FPT 2" FPT	0.1-28 GPM 0.2-44 GPM 20-130 GPM 30-160 GPM 0.5-26 GPM 0.5-44 GPM 22-140 GPM 22-176 GPM	10-150 PSI for all sizes 7-145 PSI for all sizes
Baccara: DC Latching Solenoid 24V AC Solenoid	DC AC	Globe Globe	Low Pressure Flow Control	3/4" FPT 3/4" FPT 1" FPT	0.5-22 GPM 0.5-22 GPM 0.5-29 GPM	4.3-145 PSI for all Baccara valves
DIG: DC Latching Solenoid	DC	Globe	Flow Control	3/4" FPT	0.1-28 GPM	10-150 PSI
Irritrol: 2700 Series Anti-Siphon Valve 700-1/ 700-1.5 205TF 100P1	AC AC AC AC	Anti-Siphon Globe Globe Angle Globe	Jar-Top, Flow Control Flow Control Internal Bleed, flow control Flow Control Internal Bleed, Flow Control	3/4" FPT 3/4" FPT 1" FPT, 1 1/2" FPT 1" FPT 1" FPT	0.25-30 GPM 0.1-150 GPM 0.25-30 GPM 0.5-50 GPM	10-150 PSI 5-100 PSI 10-150 PSI 20-220 PSI
Toro: P220-26-04	AC	Angle Globe	Flow Control	1" FPT	5-40 GPM	10-220 PSI
Hunter: PGV-100JT-G	AC	Globe	Jar-top	1" FPT	0.2-30 GPM	20-150 PSI
K-Rain: 7101-J	AC	Globe	Jar-top, Manual External Bleed	1" FPT	0.25-30 GPM	10-150 PSI
Rainbird: 75DVF, 100DVF 075ASVF, 100ASVF	AC AC	Globe Anti-Siphon	Flow Control Back Flow Prevention, Flow Control	3/4" and 1" FPT 3/4" and 1" FPT	0.2-22 GPM 0.2-40 GPM 0.2-22 GPM 0.2-40 GPM	15-150 PSI 15-150 PSI

To get the correct valve for your system, first think about the power source from your controller. Once you have picked the right power source, think about the pressure your system will be operating at and the flow rate each zone will be using. After reading this guide, you should be able to narrow down which valve is best for your system. If you have more questions, please feel free to call our customer service center. It is available Monday-Friday from 8 am to 4 pm PST.