In rural firefighting, ensuring a continuous and high-volume water supply can be challenging, especially when drafting from static water sources. By utilizing multiple intake drafting techniques, you can significantly boost water flow, improve pump efficiency, and overcome friction loss in your operation.

When a single intake is not sufficient for your water flow demands, you need to consider expanding your drafting system. Multiple intake drafting allows you to spread the load across several intakes, reducing friction loss and increasing the total water volume available to the pump. In this article, we’ll cover how to set up a multiple intake drafting operation and the benefits it offers.

The Importance of Multiple Intake Drafting

In a standard drafting operation, one intake is often sufficient to meet lower flow requirements. However, when higher flow rates are needed—especially in large-scale fires or rural settings—a single intake can reach its limit, causing issues such as high vacuum readings and insufficient water supply.

By incorporating multiple intakes into your drafting system, you can:

If your vacuum reading reaches 22″ of mercury, it’s time to expand your drafting system with more intakes.

Identifying When to Use Multiple Intakes

The key to knowing when to expand your system is by paying attention to your pump’s compound gauge or master intake gauge. A reading of 22 inches of mercury (Hg) indicates that your current setup is maxed out—either due to friction loss or lift. This is the signal that it’s time to add another intake.

Setting Up a Multiple Intake Drafting System

Begin with a Single Intake

Start with a single intake connection to establish an initial water supply. The key is to position the pumper close enough to the water source for efficient drafting. In many cases, nosing the pumper into the source allows for a shorter suction hose, which helps establish a quick water supply.

Add a Second Intake

Once the initial water flow is established and your pumper is running efficiently, you can begin setting up the second intake. Here’s how:

Monitor and Adjust the Pump

As soon as the second intake is in operation, you’ll notice a drop in the vacuum reading on your gauge. This is because the total flow is now being split between two intakes, reducing friction loss and improving overall efficiency.

Advanced Tips for Multiple Intake Drafting

Throttle Up to Increase Water Flow

If your current flow doesn’t meet the fireground demand after setting up two intakes, you can throttle up the pumper and open more discharges to further increase the flow rate.

By adding more intakes, you reduce the workload on the pumper and can increase water flow without straining the system.

Handling Lift Challenges

If you’re dealing with significant lift (over 10 feet), multiple intakes become even more critical. With two intakes, you can reduce the friction in each intake, allowing the pumper to operate more efficiently even with a high lift.

Dealing with Limited Horsepower

In some cases, you may find that even after setting up a multiple intake system, your pumper can’t increase the water flow due to limited horsepower. This is not uncommon, especially with older rigs or apparatus with smaller engines. In these scenarios, the limitation isn’t in the water supply but in the engine’s ability to pump more water.

Consider opting for larger horsepower motors when ordering apparatus if your department frequently operates in rural environments and relies on static water sources.

Limited horsepower is not unique to old rigs—even new apparatus may struggle with large flow operations. Consider upgrading to higher horsepower for better performance.

Maximizing Water Flow in Rural Operations

Utilizing multiple intake drafting isn’t just about increasing water flow—it’s about creating a flexible and efficient system that can scale with the demands of the fireground. Whether you’re dealing with long lifts or the need for high fire flows, this technique allows you to optimize your pumper’s performance and ensure a steady water supply.

Frequently Asked Questions About Burp Drafting

After-Action Review: Mastering Drafting with Multiple Intakes

Utilizing multiple intake drafting isn’t just about increasing water flow—it’s about creating a flexible and efficient system that can scale with the demands of the fireground. Whether you’re dealing with long lifts or the need for high fire flows, this technique allows you to optimize your pumper’s performance and ensure a steady water supply.

Tell us what you thought about this lesson!