For the best of times, educate yourself on the difference between polyurethane and EPDM liners so you can save time and money on your application!
Single and double jacket fire hoses are essentially an inner liner or tube encased within one or two layers of canvas or polyester covering. EPDM rubber is commonly found in the internal structure of fire hoses. However, thermoplastic polyurethane is a more recent technology making its way into fire hose construction.
A polyurethane lined hose.
Choosing the Right Double Jacket:
Double jacket polyurethane lined hoses are quite popular these days, but why choose a polyurethane lined double jacket over one that is constructed with the hardy EPDM liner? Polyurethane liner is sprayed inside the jacket during the weaving process, making for a slightly lighter fire hose assembly. For metropolitan fire fighting, polyurethane lined double jacket is used for the packs firefighters carry into high-rise buildings, so they can connect the manifolds and standpipes on the topmost floors.
You can imagine these firefighters would want the lightest assembly for this high rise use. Courtesy of High-Rise Operations.
Some manufacturers claim that the polyurethane liner provides better laminar flow, however, we have not seen any quantitative data to support this claim. If there were to be any flow characteristics, they would be negligible at best. Polyurethane, although somewhat lighter, is subject to accelerated embrittlement, especially if the hose is not maintained on a reel. In layman’s terms: this liner will crack when exposed to UV, drastic temperatures, or rough use, not allowing for a particularly long lifetime.
Polyurethane Liners in Single Jacket Hoses:
There are two different single jacket hoses that utilize the thermoplastic polyurethane liner: rack and reel hoses and forestry hoses. Because rack and reel hoses need to be replaced often in accordance with NFPA’s standards, the polyurethane liner allows for the purchase of the hose to be more cost effective. Forestry hose uses a polyurethane liner for a more lightweight construction so firefighters can easily carry it when faced with a forest fire.
EPDM Rubber-Longevity and Durability:
A double jacket hose with an EPDM black rubber liner.
The EPDM rubber lined hose is manufactured in a two-step process: the tube is extruded separate from the jacket(s) weave, and then inserted and pulled through the jacket, vulcanized with steam. Because the rubber bonds directly with the jacket, the EPDM liner offers a greater yield and is not subject to embrittlement, unlike the polyurethane. For rural, volunteer, and even inner city firefighting, the EPDM lined double jacket will provide a longer lifetime and proves its endurance under constant working conditions.
We understand that fire departments are often on tight budgets, which is why they must invest in the correct hose. Call your team at Rawhide and we can find that right hose!
