Is Oxygen Flammable

As NASA's final space shuttle mission nears, workers prepare to lose the jobs ...

CAPE CANAVERAL

Frank Sunderman preheated the oven to 350 degrees, just like somebody baking cookies.

But in his oven, Sunderman had placed 16 chunks of black ceramic tile onto a cloth made of glass.

Nitrogen poured into the oven, and then sucked out to create a vacuum, and later warm chemicals shot in, vaporized, and soaked through.

Sunderman has happily worked this job for 22 years, waterproofing the tiles that cover space shuttles, the same tiles that protect astronauts from the searing heat of re-entering Earth's atmosphere.

It's a job that helped him raise a family and came with a wonderful fringe benefit — he watched more than 75 launches at close range, right outside the building where he works.

But this Friday, on the very last launch in the history of the space shuttle program, Sunderman plans to stay home. That will allow him and his wife to watch the historic launch from their front yard with their 5-year-old grandson, who will be wearing a blue astronaut suit covered with mission patches.

There is another reason for staying home, however.

"It's probably going to be a little emotional," Sunderman allowed. "I don't want to let 'em to see the big guy cry."

A generation of American workers is preparing for the final shuttle launch. It's a milestone in history, but for these workers, it's personal. For many of these employees of NASA contractors such as United Space Alliance, Boeing and others, this has been their last chance to turn a wrench on a ship that leaves Earth.

These are the more than 5,000 men and women who fixed and fine-tuned America's reusable spacecraft with their own hands. They cooked the shuttles' tiles. They pumped fuel stored at 423 degrees below zero, and made snowballs out of the icy substance that collects around liquid oxygen lines. They mixed chemicals, sniffed for toxic fumes, pulled wiring out of orbiters and laced it back in. They scrubbed, tinkered, prayed, cried and cheered over behemoth rockets the rest of the nation sometimes ignored.

They came to know Atlantis, Discovery and Endeavour — and yes, the lost shuttles Challenger and Columbia — like you knew the bicycle you rode as a kid.

What many of these workers don't know, exactly, is where they and the American space program go next.

Atlantis is scheduled to lift off Friday and return to Earth on July 20, ending the 30-year space shuttle era.

4.14 Welding / Powerwash Blog

PURPOSE

The purpose of this section is to establish this Company's safe welding policies and procedures.  The objective is to prevent worker injury resulting from electric or gas welding apparatus use.

RESISTANCE WELDING

Installation

4.14.1 All equipment will be installed by a qualified electrician.  All electrical equipment installed will comply with the National Electric Code (NEC). There will be a safety-type disconnecting switch or a circuit breaker or circuit interrupter to open each power circuit to the machine, conveniently located at or near the machine, so that the power can be shut off when the machine or its controls are to be serviced.

Thermal Protection

4.14.2 Ignitron tubes used in resistance welding equipment will be equipped with a thermal protection switch.

Personnel

4.14.3 Workmen designated to operate resistance-welding equipment will have been properly instructed and judged competent to operate such equipment.

Guarding

4.14.4 Controls of all automatic or air and hydraulic clamps will be arranged or guarded to prevent the operator from accidentally activating them.

SPOT AND SEAM WELDING MACHINES (NON-PORTABLE)

Voltage

4.14.5 All external weld initiating control circuits will operate on low voltage, not over 120 volts, for the safety of the operators.

Capacitor Welding

4.14.6 Stored energy or capacitor discharge type of resistance welding equipment and control panels involving high voltage (over 550 volts) will be suitably insulated and protected by complete enclosures, all doors of which will be provided with suitable interlocks and contacts wired into the control circuit (similar to elevator interlocks). Such interlocks or contacts will be so designed as to effectively interrupt power and short circuit all capacitors when the door or panel is open. A manually operated switch or suitable positive device will be installed, in addition to the mechanical interlocks or contacts, as an added safety measure assuring absolute discharge of all capacitors.

Interlocks

4.14.7 All doors and access panels of all resistance welding machines and control panels will be kept locked and interlocked to prevent access, by unauthorized persons, to live portions of the equipment.

Flammability and sensitivity of materials in oxygen-enriched atmospheres

Flammability and sensitivity of materials in oxygen-enriched atmospheres, tenth volume

Safe use of oxygen and oxygen systems, guidelines for oxygen system design, materials selection, operations, storage, and transportation

Flammability and sensitivity of materials in oxygen-enriched atmospheres

Anaesthetic equipment