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Understanding Fire Hose Couplings and Threading

Amanda Delatorre |

Fire hose couplings and threads.

In order for a fire hose to work safely and effectively, proper coupling selection is essential. A hose coupling is a type of fitting located on the end of the fire hose, which is typically made of steel, brass, or aluminum. The coupling has threading on each end, one female end and one male end, allowing the hose to connect with another hose, tap, or other water source. In order to attach the two threaded devices together, several factors must be considered, such as size, gender, and thread standard. To better understand fire hose couplings and threading, consult this helpful guide.

Coupling gender

Hose couplings come in three different genders: male, female, and universal. The gender of a hose coupling is easy to determine by looking at its threads. Male coupling has threads on its outside and female coupling has threads on the inside. Universal coupling, on the other hand, can be joined to any other end of the same diameter rather than having a distinct male or female end.

Coupling size

To ensure that your fire hose functions properly, it’s important to choose the correct size coupling for your application. To determine the size of the coupling that your hose will require, check the number on the female coupling. Other options for determining the correct size of the required coupling include measuring the diameter of the inside of the male coupling or looking for numbers stenciled on the fire hose.

Thread standards

Understanding the different thread standards of fire hose couplings is essential for properly matching fire hose devices together. While there are many different types of fire hose threads, there are three main types that are most commonly used in fire departments. The most common types of fire hose threading are identified by the initials NH or NST, which refer to national standard thread; NPT, which stands for national pipe threads; and NPSH, which represents national pipe straight hose thread.

To determine what type of thread standard your coupling requires, check for a stamp with the initials of the thread’s standards on the female couplings of the hose you plan to replace, the water source adapter, or fitting. In the case that there isn’t a stamp in any of those locations, you can determine the thread standard by measuring the male coupling’s outside diameter, or circumference.

The Supply Cache is a leading provider of high-quality wildland firefighting gear and equipment. Our diverse inventory includes a wide range of equipment, such as hoses, adapters and nozzles, collapsible water tanks, fire-resistant clothing, and other essentials. For top-of-the-line wildland firefighter gear and equipment that will help you get the job done safely and effectively, shop The Supply Cache today.