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MK Products Positioner 1/AirCrafter T-25 User Manual

Page 4

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This includes: a thorough steam or

caustic cleaning (or a solvent of water

washing, depending on the combustible’s

solubility), followed by purging and

inerting with nitrogen or carbon dioxide,

and using protective equipment.
Water-filling just below working level may

substitute for inerting.
A container with unknown contents

should be cleaned (see paragraph

above). Do NOT depend on sense of

smell or sight to determine if it is safe to

weld or cut.
Hollow castings or containers must be

vented before welding or cutting. They

can explode.
Explosive atmospheres. NEVER weld or

cut where the air may contain flammable

dust, gas, or liquid vapors (such as

gasoline).

D. Compressed Gas Equipment

The safe handling of compressed gas

equipment is detailed in numerous

industry publications. The following

general rules cover many of the most

common situations.
1. Pressure Regulators

Regulator relief valve is designed

to protect only the regulator from

overpressure; it is not intended to protect

any downstream equipment. Provide

such protection with one or more relief

devices.
Never connect a regulator to a cylinder

containing gas other than that for which

the regulator was designed.
Remove faulty regulator from service

immediately for repair (first close cylinder

valve). The following symptoms indicate

a faulty regulator:
Leaks - if gas leaks externally.
Excessive Creep - if delivery pressure

continues to rise with downstream valve

closed.
Faulty Gauge - if gauge pointer does

not move off stop pin when pressurized,

nor returns to stop pin after pressure

release.
Repair. Do NOT attempt repair.

Send faulty regulators for repair to

manufacturer’s designated repair center,

where special techniques and tools are

used by trained personnel.
2. Cylinders

Cylinders must be handled carefully to

prevent leaks and damage to their walls,

valves, or safety devices:
Avoid electrical circuit contact with

cylinders including third rails, electrical

wires, or welding circuits. They can

produced short circuit arcs that may lead

to a serious accident. (See 1-3C)
ICC or DOT marking must be on each

cylinder. It is an assurance of safety

when the cylinder is properly handled.
Identifying gas content. Use only

cylinders with name of gas marked on

them; do not rely on color to identify

gas content. Notify supplier if unmarked.

NEVER DEFACE or alter name, number,

or other markings on a cylinder. It is illegal

and hazardous.
Empties: Keep valves closed, replace caps

securely; mark MT; keep them separate

from FULLS, and return promptly.
Prohibited use. Never use a cylinder or its

contents for other than its intended use,

NEVER as a support or roller.
Locate or secure cylinders so they cannot

be knocked over.
Passageways and work areas. Keep

cylinders clear of areas where they may

be stuck.
Transporting cylinders. With a crane, use

a secure support such as a platform or

cradle. Do NOT lift cylinders off the ground

by their valves or caps, or by chains, slings,

or magnets.
Do NOT expose cylinders to excessive

heat, sparks, slag, and flame, etc. that

may cause rupture. Do not allow contents

to exceed 55 degrees C (130 degrees F.)

Cool with water spray where such exposure

exists.
Protect cylinders, particularly valves from

bumps, falls, falling objects, and weather.

Replace caps securely when moving

cylinders.
Stuck valve. Do NOT use a hammer or

wrench to open a cylinder valve that cannot

be opened by hand. Notify your supplier.
Mixing gases. NEVER try to mix any gases

in a cylinder.
NEVER refill any cylinder.
Cylinder fittings should never be modified

or exchanged.
3. Hose

Prohibited use. Never use hose other

than that designed for the specified gas. A

general hose identification rule is: red for

fuel gas, green for oxygen, and black for

inert gases.
Use ferrules or clamps designed for the

hose (not ordinary wire or other substitute)

as a binding to connect hoses to fittings.
No copper tubing splices. Use only

standard brass fittings to splice hose.
Avoid long runs to prevent kinks and abuse.

Suspend hose off ground to keep it from

being run over, stepped on, or otherwise

damaged.
Coil excess hose to prevent kinks and

tangles.
Protect hose from damage by sharp edges,

and by sparks, slag, and open flame.
Examine hose regularly for leaks, wear, and

loose connections. Immerse pressured

hose in water; bubbles indicate leaks
Repair leaky or worn hose by cutting area

out and splicing. Do NOT use tape.
4. Proper Connections

Clean cylinder valve outlet of impurities that

may clog orifices and damage seats before

connecting regulator. Except for hydrogen,

crack valve momentarily, pointing outlet

away from people and sources of ignition.

Wipe with a clean, lintless cloth.
Match regulator to cylinder. Before

connecting, check that the regulator label

and cylinder marking agree, and that the

regulator inlet and cylinder outlet match.

NEVER Connect a regulator designed

for a particular gas or gases to a cylinder

containing any other gas.
Tighten connections. When assembling

threaded connections, clean and smooth

seats where necessary. Tighten. If

connection leaks, disassemble, clean,

and retighten, using properly fitting

wrench.
Adapters. Use a CGA adapter (available

from your supplier) between cylinder

and regulator, if one is required. Use

two wrenches to tighten adapter marked

RIGHT and LEFT HAND threads.
Regulator outlet (or hose) connections

may be identified by right hand threads

for oxygen and left hand threads (with

grooved hex on nut or shank) for fuel

gas.
5. Pressurizing Steps:

Drain regulator of residual gas through

suitable vent before opening cylinder

(or manifold valve) by turning adjusting

screw in (clockwise). Draining prevents

excessive compression heat at high

pressure seat by allowing seat to open

on pressurization. Leave adjusting

screw engaged slightly on single-stage

regulators.
Stand to side of regulator while opening

cylinder valve.
Open cylinder valve slowly so that

regulator pressure increases slowly.

When gauge is pressurized (gauge

reaches regulator maximum) leave

cylinder valve in following position: for

oxygen and inert gases, open fully to

seal stem against possible leak; for fuel

gas, open to less than one turn to permit

quick emergency shut-off.
Use pressure charts (available from

your supplier) for safe and efficient

recommended pressure settings on

regulators.
Check for leaks on first pressurization

and regularly thereafter. Brush with soap

solution. Bubbles indicate leaks. Clean

off soapy water after test; dried soap is

combustible.

E. User Responsibilities

Follow all Safety Rules.
Remove leaky or defective equipment

from service immediately for repair. Read

and follow user manual instructions.

F. Leaving Equipment Unattended

Close gas supply at source and drain

gas.

G. Rope Staging-Support

Rope staging-support should not be

used for welding or cutting operation;

rope may burn.