Fire hydrants have been in use for more
than 200 years.
In the old days their main purpose was to supply water to fight fires, but they also provided the public with a handy water supply.
Fire crews rely on the nearest hydrant to be ready at a moment's notice to help
them douse flames whenever they breakout.
Fire hydrants are essential to every
community.
They need to be instantly recognizable, easily accessible, and simple to operate.
The ones in residential areas are designed to deliver no less than an impressive 5700 liters per minute.
The hydrant making process starts with recycled scrap iron along with steel and raw iron.
Using a magnetic crane workers load the metals into a furnace and melt them at fifteen hundred thirty-eight degrees Celsius.
This turns the scrap metal into molten
iron.
Then they transfer the molten iron into a remote-controlled ladle.
And empty it into an automated pouring system.
To cast the hydrants workers first make two-part molds by compressing a mixture of sand and bonding materials.
One part called the mold forms the
hydrants exterior shape while the other part called the core forms the interior
shape.
An automatic core setter positions a core in each mold .
Then a conveyor advances the mold under the pouring box which fills the cavity between the mold and core with molten iron.
After the iron cools and solidifies the molds enter a tumbling barrel.
As they revolve the sand gradually disintegrates freeing the iron casting inside.
Workers drill and thread the hydrant
castings to prepare them for assembly.
Then they pre assemble and paint them
the color the customer requested.
The fire hydrants internal workings
called the valve assembly allow water to flow through when opened.
A series of rubber o-rings on the main valve will prevent leaks when the hydrants closed.
Now the hydrant is ready for final assembly.
Workers attach the nozzle section to the top of the hydrant barrel and attach nozzle cap chains with a crimping tool.
Using a torque wrench they attach cast
iron safety rings.
These rings are designed to disengage the top from the bottom of the hydrant so it doesn't get damaged if a vehicle hits it.
Workers clamp the water main connector into place and pressurize the hydrant to
normal city pressure to check for leaks.
Using a hoist they lower the preassembled nozzle section over the stem.
And fasten it to the water main
connector with stainless steel bolts.
They lower the bonnet into place.
Bolt it to the nozzle section.
Then open the hydrant for a high-pressure test.
They turn the operating nut to allow water to flow through.
Before conducting this test, they force out the air inside the hydrant with water.
Workers transfer the finished hydrant to
a pallet and apply final paint touch-ups.
Some fire hydrants that were installed
more than a hundred years ago are still in use today.
