A Complete Guide to Fire Hose Adapters and Fittings - MAFCO

Fire hose adapters are small but essential components that reduce firetrucks&#; weight and enhance their level of preparedness

Fire trucks in the United States are oftenlarge-size vehicles like giant

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multi-wheeled toolboxes carrying not only firefighters, but also tons of hoses, bunker gears, and water.On fire engines, small gears such as fire hose adapters and fittings play a key role in reducing firefighters&#; loads to work much lighter and smarter.

If you are looking for the right hose adapter, the best move is to shop around and do some homework to know how each fitting differs before buying. Here is your homework.

Thread types determines hose connection flexibility

Like conventional mating connectors, each of most hose fittings and adapters has a matching gender (a male or female thread) for one to connect with the other. That means the angle (pitch), spacing, and diameter ofeach thread varies widely, depending on thread styles. Mismatched thread types may cause fittings to leakor even burst off under pressure, posing serious risks to both firefighters and potential victims.

Despite regional ramifications of thread types, fire hose adapters typically meet the following most popular standards:

• Most popular: National Standard Thread/National Hose (NST or NH)
• Less popular: National Pipe Straight Hose/Iron Pipe Thread (NPSH or IPT)
• Wildfire firefighting and special uses: Garden Hose Thread (GHT)
• Fixed piping system/pressure gauge connections: National Pipe Thread (NPT)

Fittings with National Pipe Thread (NPT) cause the most controversy in the field of fire protection. The main reason is that NPT threads can screw with other NPT threads permanently while male NPT threads attach to NPSH fittings onlytemporarily. It takes a male NPSH fitting and a female NPT fitting to make a permanent connection. Here are two simple rules for NPT-threaded users to follow:

1. Connect male NPT ends to NPSH fire hoses or female NPT-threaded pipes.

2. Connect female NPT ends only to male NPT ends for permanent installation of fire pumps or piping systems.

Each fire equipment has its own thread gender 

The thread gender (male/female) of hose fittings and adapters only connect to mating inlets or outlets of the fire equipment. Generally, the equipment that discharges water has male-threaded outlets as garden hoses have while the orifices that receive water have female threads or female swivels.

Although local fire departments are given considerable autonomy by the authorities over how to pick their own equipment and threads, they still adhere to certain conventional guidelines on gendered connections describedin a nutshell as follows:

Fire hoses, with a male coupling and a female one at each end, enable firefighters to link hoses together if need be. Female swivels are used by Fire Department Connections (FDCs), which means only male-ended fire hoses can be connected to FDCs for sprinklers and standpipe systems to be supplied with water.Here are some handy hints about such connections:

1. Fire hose nozzles with female inlets should connect to fire hoses with male ends.

2. Fire hydrants have male-threaded outlets or nozzles.

3. Dry hydrants, unpressurized pipes with one end below the water level of a pond or lake, can have either male or female threads, depending on how they are installed in the rural locations worldwide.

4. Hose angle valves, an integral part of permanently installed indoor hoses, have either male- or female-threaded outlets.

5. Swinging hose racks, to attach to a double-male nipple, typically have the hose valves with female-threaded inlets.

6. Stationary hose angle valves, often found with a rack and reel hose, may use male-threaded outlets.

Fire hoses and equipment without threads

So far, we have talked considerably about the threaded fire hose adapters and fittings commonly seen on the fire protection system markets. Now we would like to mention the threadless couplings used by many hoses, valves, and pumps &#; Storz connections, which have been widely used in Europe for decades and gained increased visibility in the United States recently. ThoughStorz couplings come in large and small sizes, the US fire departments prefer 4&#; and 5&#; sizes on the following equipment:

• Fire hose couplings
• Fire department connection inlets
• Inlets and outlets on tankers or engines
• Largediameter &#;pumper nozzles&#; on fire hydrants

Certain adapters provide good connection with different threaded fire equipment

We learned the peril of incorrect fittings the hard way when Oakland Hills Fire devastated Oakland, California in .The major reason why the fire grew to an enormous scale at such a rapid pace is that the firefighters called on from neighboring communities failed to connect their standard 2 1/2&#; adapters to Oakland&#;s 3&#; hydrant connections.

We&#;ll further discuss in this section how to prevent connector mismatch in similar situations, such as:

• Firefighting units from neighboring jurisdictions combine forces (mutual aid operations)
• Newly acquired or donated equipment fail to connect to existing equipment

Storz x 4 1/2&#; NST

Usage:provide the connection between standard 4 1/2&#; hydrant inlets and large-diameter Storz hose.

Swivel Adapters &#; 1 1/2&#; or 2 1/2&#; Female NST to Male NPT (Various)

Usage: connect the swivel end of an NPSH hose to an NST-threaded hose (male), NST hoses to NPSH nozzles, or an NPSH-threaded hose to an NST-threaded port on a fire pump.

Standard sizes:

• 1 1/2&#; FNST x 1 1/2&#; MNPT
• 2 1/2&#; FNST x 2&#; MNPT

Hex Adapters &#; FNST x MNPT (1 1/2&#; & 2 1/2&#;)

Usage: connect the male end of the NST hose to the female end of an NPSH hose or fitting; NST hoses to NPSH nozzles, NST, and NPSH hoses; and NPSH hoses to NST pumps.

Standard sizes:

• 1 1/2&#; F NST x 1 1/2&#;M NPT
• 2 1/2&#; F NST x 2 1/2&#; M NPT

Fire hose fittings and adapters can perform a reverse lay much quicker

Fire engines are designed to carry hundreds of feet of fire hoses in length that would need to be handled and storedby firefighters in various ways from the &#;flat load&#; to the &#;reverse horseshoe&#; according to fireground situations.It&#;s not uncommon for a hose to be stored in the wrong direction, or for the wrong end of it to be pulled from the engine. Fire hose fittings and adapters can always be used to correct this problem without re-laying the hose.

2 1/2&#; Double Female NST

Standard uses: Connect mislaid hoses to each other or to hydrants more quickly due to swivels that many double-female adapters have.

2 1/2&#; Double-Male NST

Standard uses: Connect mislaid NST hoses to fire department connections, such as nozzles, engines, and other hoses.

Other firefighting adapters for long-term installation

It would be idealistic to think all hydrants and hoses are so compatibly arranged that there is no chance of them being mismatched anyway. In practice, however, some adapters are installed permanently to avoid such mismatches and ensure firefighters always have access to water.

Hose Rack Brass Nipples (1 1/2&#;, 2 1/2&#; NST)

Standard uses:This type of nipples is identical to most other double-male adapters except that they are longer in length and have the hex-shaped protrusion. Such features help the nipple to reach through an orifice in a swinging hose rack, thus holding the angle valve and fire hose together.

Sizes: 1 1/2&#; pin racks are typical of Class II standpipe systems and some Class III systems. Other class III systems mayhave larger (2 1/2&#;) angle valves for firefighters&#; 2 1/2&#; hose or 1 1/2&#; permanent hose (via a 2 1/2&#; x 1 1/2&#; reducer). All in all, here are the typical sizes for this type of nipples:

• 1 1/2&#; MNPT x MNST &#; Class II and Class III systems with 1 1/2&#; pin racks
• 2 1/2&#; MNPT x MNST &#; those Class III systems with 2 1/2&#; hose angle valves (reducers required)

Hex Adapters &#; 1 1/2&#; or 2 1/2&#; Double Female, Double Male, and Male x Female

Standard uses:This type of adapters permanentlyconnect pipes, pumps, and the equipment with NPT orifices to fire hoses.

Sizes and types:  Conventionally, inlets are the pipe or orifice with female NPT threads while outlets are those with male threads. The fittings that connect to NPT outlets are listed as follows based on the hose threads and the matching adapters:

Fire protection fittings and adapters may look complex at first sight

So far, you have glanced through standard uses of various adapters we presented concisely, but they are not the golden rules. A little bit creativity may make a huge difference in joining all sorts of right equipment together in no time. But you must be very careful while choosing the right equipment or adapters.Firefighters can be delayed and, worse still, their efforts might even fail due to mismatched adapters.

Grooved Fittings for Fire Fighting System: Type and Function

View JIANZHI Fire Fighting Grooved Fittings

Grooved pipe connection technology, or clamp connection technology, has become the first for liquid and gas pipeline connections. Although this technology entered China relatively late, due to its advanced technology, it was quickly adopted by the domestic market. It has been researched and developed since . After just a few years of development and application, it has gradually replaced the two traditional pipeline connection methods of flange and welding. Not only is the technology more mature, but also widely recognized by the market, and it has been actively guided by national laws and regulations.

Fire sprinkler pipe and related fittings are generally made of carbon steel or ductile iron material and used to carry water or other liquid to connect firefighting equipment. It is also called fire protection pipe and fittings. According to the corresponding rules and standards, the fire pipeline need to be red painted, (or with red anti corrosion epoxy coating), the point is to separately with other pipeline system. Since the fire sprinkler pipe usually installed in a static position, it requires a high level and restrict quality control.

The application of grooved pipe fitting connection technology makes the complex pipe connection process simple, fast and convenient. A big step forward in plumbing technology.

The following video shows the grooved pipe fittings more intuitively&#;

There are many types of grooved fittings, and different types of fittings have different functions.

1. Grooved pipe fittings are mainly divided into the following categories:

Elbow categories: including 90° elbow, 45° elbow, 22.5° elbow, 11.25° elbow, and other angle elbows; one notable specialty with the grooved elbow is a "Drain Elbow", which has the elbow except it includes a drain outlet at the bend of the elbow. This is used all the time with fire department connections that come down a wall and need to be capable of being drained (to avoid having water-charged pipe freeze and burst).

Tee type: including regular tee, groove reducing tee, thread reducing tee, medium and large tee, etc.;

Four-way type: including the positive cross, groove reducing cross, thread reducing cross, etc.;

Mechanical tee: including grooved mechanical tee, threaded mechanical tee, grooved mechanical tee, wire-connected mechanical tee, machine three lower pieces, U-shaped wire-connected mechanical tee, etc.;

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Reducer: Reducing fittings, which is a concentric, single-cast piece of metal that has a large groove on one end and tapers down to a smaller groove on another end. One note of caution is using these in the vertical orientation; It is much better, more stable, and stronger to use a reducing-fitting as opposed to a reducing-coupling when in a vertical orientation. It is including groove concentric, thread concentric, groove eccentric thread eccentric, etc.;

Flanges: including single-piece flanges (also called flange pipe clips, split flanges, flange sheets, etc.), short-pipe flanges (also called conversion flanges, grooved short pipes, high-neck flanges, etc.);

Pipe plugs: including blind sheets (also called pipe plugs, blind plates, etc.).

Grooved pipe joints: mainly rigid pipe joints, flexible pipe joints, etc.

2. Surface

The surface of the grooved pipe fittings in the fire protection system will be treated with red dipping paint, on the one hand for rust prevention, and on the other hand for easy identification (red represents fire protection).

Red fire fittings

3. 

Rubber seals

Design principle:

The sealing ring used in the grooved pipe joint realizes the sealing performance of the system by increasing the pressure. From the cross-section, it belongs to the "C" type design. The higher the pressure, the better the sealing performance.

Rubber material:

The material used for the sealing ring can be determined according to the medium conveyed by the pipeline, and different materials have different letter codes on the sealing ring. For example, EPDM rubber (code E, black) is usually used in fire engineering systems; silicone rubber (code S, the sealing ring material of the pressure cooker, is milky white) for drinking water; Nitrile rubber (code D, orange); natural rubber (code N, black). Among the products currently provided by Jianzhi Group to customers, they are mainly used in fire protection engineering and water supply engineering, so EPDM rubber rings and silicone rubber rings are commonly used.

Fittings in black EPDM

4.Rigid and flexible coupling

The pipe joint is an important part of the entire pipeline system and is the connector of the grooved pipe fittings. It is mainly divided into two types: rigid clamps and flexible clamps. Both will be used in the fire protection system. In order to avoid user selection errors, it is necessary to explain the difference between rigid clamps and flexible clamps and flexible clamps in detail.

The difference between rigid coupling and flexible coupling:

The characteristic of the rigid pipe joint is that the two adjacent pipe ends connected by it will not have the relative axial angle change and the displacement on the axis. This kind of pipe joint is mainly used in the riser pipe, empty rack pipe and other positions of the pipeline system.

The characteristic of the flexible pipe joint is that a certain relative angle and deflection are allowed in the axial direction of the two adjacent pipe ends connected by it. The allowable angle variable is related to the size of the pipe mouth, so it is also called a flexible joint. This kind of pipe joint is mainly used for buried pipes or large-diameter pipes, because the buried pipes have different degrees of ground settlement in different sections, and the bottom surface of the trenches dug for laying the pipes is not necessarily flat, which will make the two adjacent sections of pipe are not on the same level, and the flexible pipe joint can completely solve this problem because it can have axial deflection.

Use in fire protection systems:

Grooved fittings are often used for pipes in fire fighting systems. It is not uncommon for both mains and branch lines to be grooved today.

1&#;Rigid joints can be widely used in indoor fire pipelines with little temperature difference. However, a certain number of flexible joints should be installed in the middle section of the long straight pipeline to compensate for a small amount of thermal expansion of the long straight pipeline section and ensure the safe operation of the entire pipeline system.

Indoor fire pipeline

2&#;It is recommended to use flexible joints for pump room piping to reduce noise and weaken vibration transmission.

Pump room piping

3&#;The buried pipelines in the fire protection system should adopt flexible joints, which can effectively deal with the local deformation of the pipeline system caused by uneven settlement.

4&#;For the connection of small arc-shaped pipes, flexible pipe joints must be used. It can be assembled according to the straight pipe first, and then the pipe can be turned to make it reach the predetermined angle. However, in any case, the angle of rotation shall not exceed the value specified in the specification of grooved pipe fittings.

5. Summarize

The construction of a fire-fighting system pipeline is a huge and complex project. This article only briefly introduces the types and functions of grooved pipe fittings for fire-fighting systems. If you're looking to explore the extent of all available grooved fittings, I'd invite you to check out JIANZHI's catalogs for grooved pipe fittings. The JIANZHI's grooved fittings data can do a whole lot of good in clarifying what's been created and listed for use in firefighting systems. If want to learn more, you can also continue reading other articles on this site. Of course, if you are interested in our grooved pipe fittings, please contact our salesmen through the contact information displayed on this website. Our salesmen will give you professional answers.

JIANZHI provides fire sprinkler pipe and fittings, products approved by UL and FM. If you have any requirements or any doubts we can be helped, just contact us.

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