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How to Buy Fire Hose
A fire hose is one of the most important tools you need to purchase. As such, there are several critical decision making factors that impact on that buying decision. Whether the decision is for purchasing in-plant hose for fire brigade or occupant use, wash down hose, forestry hose, or if the decision is being made for aggressive interior fire attack operations by a municipal fire department, there are several items that are common to all decisions.
There are many different types of fire hose. Each type has a specific application and there is always a “best choice” depending on the application. In some cases, the most expensive hose is not the correct hose for the application. Likewise, the cheapest hose is not necessarily the best value for the application. Look for the following in your decision process.
Hose Jacket (Cover)
The hose jacket or cover is the outside of the hose. For hose with a jacket on the outside, the outside of the hose provides some of the structural integrity of the hose. For hose with rubber on the outside, the outside of the hose provides no structural integrity to the hose. Because hose with a jacket on the outside gets structural integrity from the outer jacket, it is a good idea to get a higher burst pressure on this style of hose, as the actual burst point of the hose goes down as the outer jacket wears. There are several hose covers to choose from.
* Cotton
* Cotton/Polyester
* Nylon
* Polyurethane
* Nitrile Rubber
* Spun Polyester
* Filament Polyester
Covers generally fall into two categories: Industrial and Municipal. Industrial hoses usually have a single cover while municipal hoses have a double jacket or a rubber cover. Application is the most important thing to consider when making a decision concerning the type of cover to select. The most premium hose has a filament jacket over an extruded liner. Next would be a rubber-covered hose with a cover made of Nitrile rubber, followed by hoses covered with nylon, and then hoses covered with spun polyester. Cotton and cotton polyester blends are mostly used in forestry hoses and need to be pre-treated to prevent mildew attack. Covers can be coated to add color and to assist in abrasion resistance.
Coatings
Manufacturers coat their hoses with a product that will assist nylon and polyester with their inability to withstand abrasion, these coatings also help in reducing water pick-up. Coatings are also used for color-coding hoses. Manufacturers used to use the chemical Hypalon, manufactured by the DuPont Company; however, EPA restrictions have stopped the use of Hypalon on fire hose. Nylon hoses will always be coated. Filament polyester and spun polyester does not need to be coated. Premium coatings are polyurethane based.
Hose Liners
Generally, hose liners fall into one of several categories:
* Polyurethane Lined
* Rubber Lined
* Thin Walled Rubber Lined
* Extruded Nitrile Lined
* Extruded Polyurethane Lined
* Neoprene Lined
The basic purpose for a fire hose liner is to keep the water in the hose. It’s that simple, however, the liner of the fire hose also impacts on several other major decision concerns. Generally, an EPDM liner is better for jacketed hose, and Nitrile rubber is better for an extruded hose. Other concerns in the area of liners are: Is the hose to be used for potable (drinking) water. If so the hose must be approved by the N.S.F. (National Sanitation Foundation). The NSF is the NFPA of the drinking water world.
Polyurethane liner. In the 70’s polyurethane was experimented with to try to find a lightweight hose. While the polyurethane keeps the water in, there are several trade-off’s for the lightweight. Polyurethane liners cause the hose to have a very high friction loss. Also, polyurethane lined hoses tend to be less durable; both from a liner adhesion point of view and from a heat resistance point of view.
Rubber liner. SBR rubber is the old rubber technology. The rubber had to be relatively thick to allow for flaws in the rubber so as not to have leaks. Also, the attachment method of the liner to the hose jacket was to have an extra piece of rubber attached to both the liner and the jacket. This makes for thick and heavy hose.
Thin walled rubber liner. Usually made with EPDM rubber, this liner is lighter in weight yet has good adhesion and flow characteristics. It is also resistant to UV and ozone. The automotive industry has switched to this type of rubber for your car.
Extruded rubber liner. Usually Nitrile rubber. This liner has the best chemical resistance, abrasion resistance, and flow characteristics of all the liner materials.
Extruded polyurethane liner. Ideal for potable water. Expensive and too rigid for everyday attack hose.
Neoprene liner. Neoprene lined hoses are used in underground mining operations.
Friction Loss. The energy lost as water travels through hose is called friction loss. Friction loss is impacted by the coarseness of the liner diameter, and the liner’s ability to swell. The best liner in the area of friction loss is the extruded Nitrile rubber liner, followed by the thin walled EPDM rubber liner. The worst liner from a friction loss point of view is the polyurethane liner.
Friction loss is variable by manufacturer. Ask for actual friction loss data as tested by U.L. or some other independent source. Do not accept theoretical data. For example, there is 5” hose available with friction loss as low as 3.4 p.s.i. at 1000 gpm. According to the NFPA handbook, there is 5” hose available with friction loss as high as 8.8 p.s.i. at 1000 gpm. Functionally, what that means is one hose could flow 1000gpm 1000 feet away from a 34 p.s.i. hydrant while, it would take an 88 p.s.i. hydrant to do the same thing with another hose.
Warranty. Most manufacturers have a one-year warranty on materials and workmanship. This warranty should be non-prorated. The hose and couplings should be warranted through the hose manufacturer and hose dealer.
Chemical Resistance. Even though you may not be working in an environment that has chemicals around, chemical resistance of fire hose is also a measure of quality. Ask your manufacturer for a chemical resistance chart. In those cases where chemicals may be encountered, there are some liability issues that need to be addressed when giving a person a hose that is used under pressure in an environment that may damage the hose while being used. You may want to carry Nitrile rubber covered hose on your haz-mat unit for example. You may need to consult your insurance underwriter. There are premium hoses available that have chemical resistance warranties. Nitrile rubber hoses are the most chemical resistant fire hoses.
Abrasion Resistance. Abrasion resistance is one of the best measures of fire hose durability and longevity. There are two primary measures of abrasion resistance, the U.L. method, and the F.M. (factory mutual) method. In both cases, a higher number is a better number. The minimum requirement for the U.L. method should be no less than 2000 cycles using the standard 219 procedure. The minimum requirement for the F.M. method should be no less than the 12,000 cycles using the standard 2111 method.
Heat Resistance. For those applications where heat resistance is a concern, such as municipal fire fighting or industrial applications where sparks, such as welding operations are found, a heat resistant hose is needed. The most heat resistant fire hose is a through the weave rubber covered hose, (1200 degrees F) followed by a filament covered hose with a through the weave liner (1000 degrees F). The worst hose from a heat resistance point of view is a lightweight polyurethane lined hose, these hoses will only withstand approximately 450 degrees F. There are hoses available with burn through warranties.
What is Hose Size?
Hose size can be determined by identifying the flow desired and the distance away you need to flow it. It is also a function of hose style that can generally be put into one of two categories: Double Jacket or Extruded Rubber. The below charts show the smallest size hose that can be used for the gpm and distance combination.
DOUBLE JACKET HOSE
Hose Length in Feet
Hose Flow 100 150 200 250 300 350 400
100 gpm 1” 1-1/2” 1-1/2” 1-1/2” 1-1/2” 1-1/2” 1-1/2”
150 gpm 1-1/2” 1-1/2” 1-3/4” 1-3/4” 1-3/4” 1-3/4” 2”
200 gpm 1-3/4” 1-3/4” 1-3/4” 2” 2” 2-1/2” 2-1/2”
250 gpm 1-3/4” 2” 2” 2” 2” 2-1/2” 2-1/2”
EXTRUDED RUBBER COVERED HOSE
Hose Length in Feet
Hose Flow 100 150 200 250 300 350 400
100 gpm 1” 1-1/2” 1-1/2” 1-1/2” 1-1/2” 1-1/2” 1-3/4”
150 gpm 1-1/2” 1-1/2” 1-1/2” 1-1/2” 1-3/4” 1-3/4 2”
200 gpm 1-3/4” 1-3/4” 1-3/4” 1-3/4” 1-3/4” 2” 2”
250 gpm 1-3/4” 1-3/4” 2” 2” 2” 2” 2”
*Above charts based on maximum engine pressure of 250 p.s.i
Some specialty hoses can flow 250 gpm over 250 feet in the 1-3/4” size. Consult manufacturer for more detailed information concerning type and brand of hose you use. Nozzle type and maximum allowable engine pressure are factors to consider when selecting attack lines.
Ozone Resistance. Many areas are affected by ozone, especially power plants and sites with many electric motors and equipment. In addition, many cities rate high in ozone. Heavy concentrations of ozone pollutants and UV rays will cause hoses to crack. In double-jacketed hoses, you will not be able to see the cracks in the liner. U.L. has a listing for ozone resistant fire hose. The best hose for ozone areas are rubber-covered hoses that are U.L. listed and labeled as ozone resistant.
Markings. There are several markings to look for. For industrial applications, look for a U.L. listing of FM approval. For municipal applications, look for NFPA markings and/or U.L. listing. U.L. only lists 1-1/2”, 2-1/2”, 4”, and 5” sizes. For drinking water hoses, look for NSF approval. Hoses used in underground mining must be MSHA approved. The Coast Guard uses U.L. as their third party listing. Markings on hoses is usually done with some type of stenciling ink, this ink wears off over time. Some hoses are available with all of the stenciling information woven right into the jacket.
Couplings. Ideally, the hose and hose coupling should be made by the same manufacturer; although, this is not always possible. Attack hose couplings should have a tapered bowl and only have two lugs so as not to get caught while being dragged through the combat environment. Couplings should be manufactured to NFPA coupling specifications standard number 1963, on STORZ type couplings make sure only to purchase the locking type, also make sure that the locking mechanism is held in place on both sides of the lock. Make sure that bolt heads are not exposed.
Reparability. Rubber covered hoses have the added feature of being repairable. While more expensive than conventional hoses, this feature reduces the long-term cost of the hose. Not all manufacturers have field reparability.
Kink Resistance. Kinks in industrial hoses increase work stress and reduce productivity. Kinks in fire hoses can reduce water flow, which puts the user in danger. Rubber covered and jacketed hose with an extruded liner are the most kink resistant and are the safest. Low- pressure nozzles cause hoses to kink more.
Reflectivity. Hoses are now available with varying degrees of reflectivity. At the top of the line, you can get hoses with woven in reflective arrows indicating the way out. Other hoses are available with varying degrees of reflective stripes, ranging from woven in pin stripes to painted on stripes with reflective paint. Some manufacturers offer reflective material on their couplings.
Weight. While the dry weight of hose should be a factor in evaluating hose, the more important measure is the weight after pick-up. Hose being used in a wet environment, most of the time picks up water weight. In some cases, the hose weight doubles when wet. Application weight affects the user more than dry weight. There is a water pick up specification in the military hose spec Mil-H-24606. Rubber Covered hoses do not pick up any water weight and there are jacketed hoses that will pick up as little as three pounds when tested to the Mil H test procedure. Hose size is a big factor in hose weight. Ideally, use the smallest hose that will deliver the maximum water.
Hose Weights Including Water
Average hose, coupling, and water per 100 feet
Hose (lbs.) Coupling (lbs.) Water (lbs.) Total (lbs.)
1-1/2” 31 1 78 110
1-3/4” 35.5 1.5 104 141
1-3/4 30 1.5 104 135.5
2” 39.5 1.5 136 177
2-1/2” 53.5 2.5 223 279
3” 66.75 3.75 306 376.5
4” 77.25 7.75 544 629
5” 98.5 10.5 850 959
Supply Hose vs. Attack Hose
Supply Hose and Attack Hose are the designators that the NFPA assigned to delineate pressure categories of hose. Supply hose is used at or below 185 p.s.i. and Attack hose is used at pressures above 185 p.s.i. Unfortunately, these categories are miss-named, as you can attack with supply hose and you can supply with attack hose. These titles have confused many fire departments. By virtue of its higher friction loss, double jacket hose needs to have a higher burst pressure than rubber-covered hose. This “catch 22” situation forces double jacket hose into the high-pressure category. By contrast, rubber covered hose can operate at lower pressures to achieve the same results, forcing it into the supply category. Again remember that you can supply with attack hose and attack with supply hose.