All language subtitles for S10E08 - Fire Extinguishers; Doughnuts; Shock Absorbers; Banjos (1080p AMZN WEB-DL x265 Garshasp)_track3_[eng]

Narrator:
Today on "How it's made"...

Fire extinguishers...

...Doughnuts...

...Shock absorbers...

...And banjos.

The first fire extinguisher
On record

Was built in europe
In the middle ages.

It worked like a giant syringe
That squirted water at a fire.

The modern extinguisher uses
Compressed air as a propellant

And douses the fire with
Flame-retardant liquid, powder,

Or foam.

Squeezing the lever
Opens a valve

That releases compressed air.

The pressure then propels
The chemical through the hose

And out the nozzle.

Production of the release valve

Starts with cylindrical pieces
Of aluminum called blanks.

A carousel runs each one through
16 different machining stations.

At each stop,
Under a shower of lubricant,

Tools shape the blank
For 6 1/2 seconds.

As each blank
Completes the circuit,

It comes off the carousel.

From blank to valve
In a minute and a quarter.

Now the fire extinguisher's
Aluminum handle

Is riveted onto the valve.

It pivots on a pin.

Next, an aluminum lever
Is riveted onto the handle.

This is the lever you squeeze
To use the fire extinguisher.

Then comes the valve stem --
The valve's inner workings.

Workers simply place it inside,

And an automated
Assembly machine does the rest.

It positions a spring
Over the stem

To create resistance
When you squeeze the lever.

Then comes a retainer

To hold both the stem and spring
In position.

Now workers slip on
A plastic thimble

To position the rubber "O" ring
That goes on next.

The "O" ring acts as a seal
Between the valve and cylinder

So nothing leaks out.

The siphon tube runs from the
Valve down into the cylinder.

The firefighting chemical
Goes up this tube,

Then out the nozzle.

The compressed air
Inside the cylinder

Is what propels the chemical.

This gauge shows
If there's sufficient pressure

For that to happen.

After coating
The gauge's threaded stem

With sealant to prevent leaks,

A worker screws it
Onto the valve.

The valve unit is now
Fully assembled, tested,

And ready for installation
On top of the cylinder.

To attach it, the cylinder needs
A threaded collar.

With the help of a press,
A worker positions it.

The cylinder also needs
A bottom.

The technique this factory uses
To fuse the bottom and collar

Is called brazing.

It's similar to soldering

But with a copper ring
As a bonding metal.

After positioning a brazing ring

At the base
Of the open cylinder,

A steel bottom
Is pressed into place.

Then workers position
A brazing ring over the collar.

Now into a brazing furnace
For an hour and 45 minutes.

The 2,000-degree heat
Melts the two copper rings,

Boding the parts they connect.

Next stop,
The static-paint booth,

Where workers apply
A positive electrical charge

To the paint particles

And a negative charge
To the cylinders.

This draws the paint
Onto the surface evenly.

Then it's into an oven for
45 minutes to bake the paint.

Once the cylinders cool,
Automated machinery fills them

With a fire-extinguishing
Powder.

The main ingredient
Is a form of ammonia.

When it's sprayed on a fire,

The heat melts the particles
Of powder,

Fusing them into
An oxygen-blocking blanket

That smothers the flames.

After the cylinders are filled,
An automated machine

Screws a valve
Onto the collar of each one.

Now it's time to pressurize
The cylinder.

The lever is squeezed
To open the valve,

Enabling a compressor
To fill the cylinder with air.

They keep filling until the
Air pressure reaches 13 bars,

About six times the pressure
In a car tire.

Next, workers screw on
The nozzle

And install a locking pin.

This immobilizes the lever

So the extinguisher
Can't discharge accidentally.

As the instruction sticker says,
In case of fire,

You just pull the pin, aim,
And spray.

This mounting bracket lets you
Hang the fire extinguisher

In an accessible spot so it's
Close at hand if you need it.

When we return, frying up one
Of america's favorite treats.

Narrator: doughnuts
Used to be called oily cakes

Because they were deep fried
In pork fat.

When dutch pilgrims first
Brought them to america,

They were ball-shaped.

But then someone found

That removing a nut of dough
From the center

Helped them cook
Far more evenly.

And so the doughnut was born.

In the world of doughnuts,
There are two basic types --

Yeast doughnuts
And cake doughnuts.

The batter for cake doughnuts
Drops from the mixer

Right into
Boiling vegetable oil.

The nozzles shape the dough
As it passes.

The doughnuts fry
For about a minute and a half.

Then a conveyor carries them
Out of the vat to cool.

Yeast doughnuts
Require more time to make.

A high-speed mixer
Works the yeast dough,

Then workers pull it off
The machine into bins.

From there,
It goes into a hopper

That extrudes the dough
As a sheet.

Then it's on
To another conveyor belt

Where a series of rollers
Flatten the dough sheet

To just 3/4 of an inch thick.

The sheet passes under a shower
Of cinnamon...

Then hits a rotating cylinder
That rolls it into a log.

A small metal rod sprinkles
The dough with water.

This keeps it sticky enough
To hold its shape

While going under
Another flattening roller.

A dusting of cornstarch
Keeps the dough from sticking

To the blade that now cuts it
Into pieces.

A retractable arm drops the
Blocks of dough four at a time

Onto wire-mesh trays.

Then it's off to the proofer,

A machine much like
A large bread box

In which heat and humidity
Help the yeast dough rise.

This leavening process
Takes about 20 minutes,

During which time the trays --
Over 300 of them --

Go up and down
And then out to the fryer.

A gate slows the doughnuts down
Just before the drop

So they slide in
Without splashing hot oil.

Gas burners keep the oil
At a constant boil.

Anything less and the doughnuts
Would come out partly raw.

Halfway through, they get a flip

So they'll cook evenly
Throughout.

After two minutes,
The doughnuts leave the fryer

And move through a curtain
Of sweet glaze.

A strong air current
Blows off the excess.

And these fry cakes
Are ready to eat.

They gradually cool

As they spiral through
The production area

On their way to packaging.

Now let's see how they make
Doughnuts with filling.

A machine separates the
Yeast dough into little blobs,

Then sends them rolling
Down plastic tunnels.

This shapes them first
Into pucks,

Then into round dough balls.

Rollers then flatten the balls

Before they enter the proofer
To rise.

There's cornstarch everywhere to
Prevent the dough from sticking

To the machinery
Or to the conveyor belt.

Row after row of doughnuts
Fry in hot oil...

Then slide into a large drum
That tumbles them around,

Covering them
With a sugary coating.

Now it's time for the doughnuts
To get filled.

These nozzles inject
Just the right amount of jelly.

Each worker
Fills 45 doughnuts a minute.

After filling, these doughnuts,
Known as bismarcks,

Are ready to go on to packaging.

They're just one of the many
Delicious varieties

That this factory turns out
On a daily basis.

Next, the shocking truth

Behind one of your car's
Most critical parts.

Narrator: shock absorbers do
More than just smooth your ride.

They counteract the bounce
When you hit a bump,

Holding your tires to the road.

Without that traction,
You could lose control.

So by affecting steering,
Stopping, and stability,

Shocks are actually
A vital safety component.

Wheel vibrations cause a piston
Inside the shock absorber

To force oil through a valve.

This absorbs energy,
Reducing the vehicle's bounce.

All this happens within
The shock's two tubes --

The reserve tube and, inside it,
The pressure tube,

Housing the piston rod
And compression valve.

Both of these tubes

Are made from a steel sheet
Sliced into strips.

Inside this tube mill,

Coolant prevents the passing
Strip from overheating

As one forming roller
After another

Gradually rounds it into a tube.

Then, a copper welding wheel
Fuses the tube closed.

As the 6-yard-long tube
Comes off the mill,

A cutting tool chops it
Into shock-absorber lengths.

The tube-making process
Is the same

For the reserve
And pressure tubes,

Except that the reserve tubes
Undergo one extra step --

Compressing the ends.

This enables the shock
To house a larger reserve tube

That can hold more oil.

The reserve tube's final stop
Is a press.

A die inside
Stamps the part number,

The manufacturing date,
And the brand name.

Many components are made
Of powdered metal --

Mostly iron powder mixed with
Some graphite and copper.

After a press compacts
The powder in a die,

A furnace fuses the particles.

This powdered-metal part
Is the valve

Through which the piston
Forces the oil.

Steel discs and a spring
Help control the speed

With which the valve operates
For varying driving conditions.

A stamping tool
Crimps the end of the tube,

Holding the spring in position.

The valve, now fully assembled,

Seals the bottom
Of the pressure tube.

Meanwhile, a press punches
Round steel discs

Into other components.

These loops mount the
Shock absorber to the vehicle.

A worker positions a cup
On each one,

Then a robot
Welds them together.

They insert a cup-and-mount unit
On one end of the reserve tube,

Then weld it on.

This unit is called
The base assembly.

The base assemblies
Now go on a conveyor,

Open end up so that workers

Can drop a pressure tube
Inside each one.

Automated injectors now fill
The tubes with oil

That's specially designed
To maintain its consistency

Despite changes in temperature.

Next comes the head assembly,

Which includes
The steel piston rod

And the mount on the other end
Of the shock absorber.

Two copper welding wheels
Fuse the head assembly

To the base assembly with a cap.

This closes the unit,
Sealing the oil inside.

Next, workers weld on
A dirt shield --

A steel casing
That prevents dirt

From hindering the movement
Of the piston rod.

A piece called a bushing
Is pressed into each mount.

This helps tone down
The vibrations

Coming from the vehicle.

Now it's on
To an automated carousel.

Robots pierce a hole in each
Shock and inject nitrogen gas

To prevent the oil inside
From foaming.

After injection,
The robot seals the hole

By welding on a tiny steel ball.

And now
For the finishing touch --

An electrostatic paint job.

A machine runs
A positive electrical current

Through the shocks

And a negative one
Through the paint particles.

Like a magnet,
The static electricity

Draws the paint onto the shocks
In a flawless coat.

In the factory's
Quality-control lab,

Technicians use
Sophisticated equipment

To evaluate how well a shock
Dampens movement

At different speeds.

The tube-and-valve configuration
Inside varies by vehicle,

So the shocks
On a ground-hugging sports car

Are quite different
From those on a luxury sedan

Or on a light truck.

Coming up, a production line

That comes with strings
Attached.

Narrator:
The twang of the banjo

Resonates in american
Country music and bluegrass,

But this down-home sound

Actually has its roots
In africa.

Slaves brought to america
Wanted something

That sounded like
The instruments from home,

So they devised the banjo.

And the rest is music history.

[ "Yankee doodle" plays ]

To make a banjo,
A lip is carved into wood

That's been steamed
And bent into a circular rim.

The rim is carefully measured.

It must be a perfect fit
For this metal tone ring.

The wooden back of the banjo
Acts as a sound resonator,

And some plastic trim gives it
A more stylish look.

A chemical accelerator
Helps the glue dry

So the plastic trim adheres
Almost instantly.

The surface is then sanded

Until the plastic is flush
To the wood.

This long piece of wood
Will become the banjo's neck.

Using a table saw, an artisan
Cuts a long slot into the neck

So that a metal adjusting rod
Can be installed later.

He widens the end of the neck
With two pieces of wood

To form the instrument's
Peg head.

Next comes
Some very delicate work,

As tiny mother-of-pearl
Decorations

Are embedded
In a piece of ebony.

That inlaid piece of ebony

Is then glued onto the banjo's
Peg head and clamped to dry.

Now it's over to a saw
With 22 blades.

A long piece of ebony
Is passed over those blades

To make the banjo's fret slots.

This is the banjo's fingerboard.

Once it's been adorned
With more inlaid decorations,

The fingerboard is glued
Onto the banjo neck.

Next, the edges
Of the banjo neck and peg head

Are trimmed down to size.

Using this router,
Artisans give the back

And sides of the banjo neck
Smoother contours.

The rounded edges will make
The instrument easier to hold

And play.

They finalize the shape
Of the neck with a rasp,

Then give it a thorough sanding.

Here, metal frets are tapped

Into the slots
On the fingerboard,

And the overlap is trimmed.

Now it's time
For a little color.

Stain is rubbed
Onto the banjo parts.

When the stain dries,

It's followed by 12 coats
Of lacquer...

And finally, a thorough buffing.

Now all the pieces
Come together,

Beginning with the pre-fitted
Tone ring and wooden rim.

The plastic head through which
The banjo's sound will radiate

Fits on the tone ring.

The head is secured
With a tension hoop

And a series of hooks.

Tightening these hooks
Will stretch the plastic head

To adjust the instrument's tone.

The banjo neck and its peg head
Are attached

And secured with metal rods.

The tuning pegs are screwed
Into the peg head.

Then the banjo's strings
Are attached and tightened.

This little wooden bridge
Sits on the plastic head

And is only held in place
By the tension of the strings.

Finally, the back of the banjo
Goes into place.

And now this finely crafted
Instrument

Is ready to strum away.

[ "Yankee doodle" plays ]

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Www.Vitac.Com

Captions paid for by
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