Necessary conditions to cause a dust explosion
In the former pieces we learned the large diameter layflat hose (LDLH). That it has become the necessary equipment for USA firefighting bureau. Next, let’s talk about the type and size.
Structure
With the popular of LDLH, people begin to improve it for special demand. While they add low pressure water hose for aerial ladder truck. But Storz joint makes the screw more hulking. Earlier flayflat hose is heavy double-layer. However, it has been replaced by the light synthetic fibre. Thus LDLH develop greatly in type and spec.
Size
In America, any layflat hose over 2.5 inch belongs to LDLH. Generally they are 4 inch (100mm) and 5 inch (130mm).
If the 4 inch hose directly connect to the fire hydrant, it can transfer to 300 meters at 1900L/min. But if add a pump, the flow can be 2850L/min with the same distance. Compared with more larger size hose, this one is light in weight, low cost and small volume. Thus it’s suitable for water transfer in limited distance.
However, 5 inch hose greatly improves the transfer distance. But there is just a little increase on weight, cost and volume.
Because of above reasons, 4 inch and 5 inch LDLH has been the most general layflay hose in America. While the length is commonly 250 and 300 meters. But in San Francisco, special lay machine can set 1500 meters.
As for the large area districts, they can use even more larger layflay hose. Presently, some places begin use 6-12 inch hose. But the 6 inch hose is for the place requires large flow. While 8 inch and larger hose seldom used in firefighting. Because they are heavy and hard to operate.
We can see not all the large diameter layflat hose suitable for firefighting. Thus you have to choose a proper one. But if you have no idea, just contact Orientflex. We will offer you the best solution.
Related posts
