Sep. 02, 2024
Hardware
Fire-fighting pipes and fittings are the most basic components of the fire-fighting system, connecting fire-fighting equipment, and delivering fire-fighting water.
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Due to special requirements, the thickness and material of fire pipelines have special regulations, and they are sprayed with red paint. Fighting Pipes and Fittings must have the characteristics of pressure resistance, corrosion resistance and high temperature resistance.
Standardized fire piping facilities
As a standardized industrial product, fire pipes and fittings are strictly divided into different specifications. If buyers want to buy suitable products, they must have a clear understanding of these specifications.
Now, let's follow this guide to learn what to look out for when selecting fire pipes and fittings.
1. Selection of Fire Fighting Pipe Types
Pipe type is an important factor affecting the quality of pipe grooved connections. Most of today's fire pipeline facilities are connected by grooves. For the advantages of grooved connections, you can refer to the following:
Grooved Couplings: The Fastest Way to Connect Pipe
The groove connection method is suitable for a wide range of pipeline types. "Technical Regulations for Grooved Connection Pipeline Engineering" (CECS151:) points out: "The groove connection method can be used for galvanized welded steel pipes and welded steel pipes, galvanized seamless steel pipes and seamless steel pipes, stainless steel pipes, etc.&#; However, since the form of the weld has a certain influence on the quality of the steel pipe groove connection, the weld seam of the welded steel pipe is prominent, which is not conducive to the pressure groove of the steel pipe. Therefore, seamless steel pipes should be the first choice during installation and construction, followed by straight seam welded pipes, and spiral welded pipes should be avoided. If it is necessary to use the spiral welded pipe, the corresponding grooved pipe fittings should also be used.
2. Quality requirements for Fire Fighting pipes
Since the grooved pipe fitting is engaged with the outer wall of the pipe, excessive deviation of the outer diameter of the pipe will cause the pipe to not match the clamp, which will cause the joint to seep. In addition, unqualified pipe material, weak galvanized layer, and insufficient thickness of the pipe wall may cause the pipe to break, the galvanized layer to fall off in large quantities, or the high-frequency weld to crack, which will eventually lead to water seepage or rupture of the joint. Therefore, strict control of pipe quality is essential. All kinds of pipes should comply with the corresponding national standards. For example, galvanized welded steel pipes should meet the requirements of "Galvanized Welded Steel Pipes for Low-Pressure Fluid Transport" (GB/T), and seamless steel pipes should comply with "Seamless Steel Pipes for Fluid Transport" ( GB/T), the plastic-coated galvanized welded steel pipe and the plastic-coated seamless steel pipe shall meet the requirements of "plastic-coated composite steel pipe for water supply" (CJ/T). In addition, the wall thickness of the steel pipe shall also meet the minimum wall thickness requirements.
3. Roundness control of nozzles
Insufficient roundness of the nozzle is an important reason that affects the quality of the pipe groove connection. Before construction, the roundness of incoming pipes should be checked. The inspection can be carried out according to the following methods: Divide the pipe section into 8 equal parts, measure 4 diameters respectively, and compare them with the standard value. Where the roundness is not up to standard pipe sections should be rounded or cut off. The roundness of the pipeline is not up to standard, which is often caused by the collision of the pipeline or the extrusion of the pipes during transportation or loading and unloading. China has good experience in pipe transportation. The engineers and technicians in this country have adopted the method of installing a cross support frame at the pipe end, which has solved the problem of pipeline compression and deformation, which is worth learning and popularizing.
4. Choice of sealing ring
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. 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). Therefore, in fire protection projects, black EPDM rubber rings must be used.
Fire fittings with black EPDM seals
5. Rated working pressure of Fire Fighting grooved fittings
Rated working pressure refers to the maximum allowable working pressure of grooved fittings under working conditions, expressed in megapascals (MPa). At present, the rated working pressure of grooved fittings produced by various manufacturers in China is basically the same, namely, Grooved pipe fittings (such as elbows, tees, crosses, etc.) are generally 2.5Mpa; while threaded reducing tees and crosses; threaded mechanical tees and crosses; threaded flanges and other threaded pipe fittings are usually is 1.6MPa. The number of kilograms usually mentioned in engineering refers to the pressure of kilograms per square centimeter. Its code is Kgf/&#; 2, and its relationship with Mpa is 1Mpa&#;10 Kgf/ cm2.
The pipe fittings show a pressure capacity of 2.5MPA
6. Standard for grooved pipe fittings:
Chinese Standard: Grooved pipe fittings belong to the automatic sprinkler system, design standard GB .11-; technical specification GB/T -.
International Standard: American Design Standard AWWA C606; International Standard ISO .
Groove connection standard: ASME B36.10, ASTM A53-A53M, ISO.
7. Material standard of grooved pipe fittings
China requires that the material grade should not be lower than QT450-10;
Tensile strength σb (MPa): &#;450
Conditional yield strength σ0.2 (MPa): &#;310
Elongation δ (%): &#;10
Hardness: 160&#;210HB
Chemical element content: carbon C: 3.70-4.00; Si: 2.15-2.93; Mn: 0.46-0.66; S: 0.010-0.016; P: 0.027-0.07; Mg: 0.027-0.050; Re: 0.026&#;0.043
Learn more
I believe that after reading this guide, you already have a certain understanding of fire fighting pipes and fittings.
If you want to know more, please click the link below to enter the official website of Jianzhi Group, where there is more knowledge about fire pipe fittings.
https://www.malleableiron-pipefitting.com/industry-knowledge/
Want more information on fire fighting fittings? Feel free to contact us.
Further reading:Fire trucks in the United States are oftenlarge-size vehicles like giant
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:
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:
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:
Usage:provide the connection between standard 4 1/2&#; hydrant inlets and large-diameter Storz hose.
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:
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:
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.
Standard uses: Connect mislaid hoses to each other or to hydrants more quickly due to swivels that many double-female adapters have.
Standard uses: Connect mislaid NST hoses to fire department connections, such as nozzles, engines, and other hoses.
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.
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:
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:
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.
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