Evening star. [volume] (Washington, D.C.) 1854-1972, 1911-01-21
FIRST USE HERE Of THE
NEW WELDING METHOD
Employed in Installing Cold
Storage Plant for Agri-
cultural Department.

FIreless welding Is being demonstrated
on a practical scale in the grounds OF
the Department of Agriculture. They call
1t fireless welding. This does not mean
that it is done without heat, but there is
no forge or the other appurtenances
usually connected with welding opera
tons. The unique scheme Is being used
in connection with the cold storage plant
that is being installed for the depart
ment This plant is OF the usual brine
and ammonia type of refrigeration. The
ammonia pipe runs underground from the
powerhouse Of the department to the east
wing of the main Agricultural Depart
ment building. There are 800 feet Of pipe
now installed without joint.
First Use In Washington.
The welding scheme has been known
to the scientific world for a year past,
but p r. McCrary, the engineer install
ing the plant, is using 1t in Washington
for the first time. It consists of using a
mixture of iron oxide and aluminium fl
about a pint and half. On top of this
is sprinkled spoonful Of magnesium
flash powder such as is used in taking
fiashlight photographs.
This is fired with a match and when 1t
starts the oxide and aluminium mixture to
burning it makes a molten liquid that is
a good deal hotter than white hot iron.
White heat is known as welding heat In
iron working parlance.
The ends Of the pipe to be Joined are
squared of perfectly true and fitted to-
gether. Then the break is surrounded by
q little two-piece iron mold with hole
In the top. The two pieces of pipe are
gripped by wise that can be screwed
up SO that the squared on ends are
crowded together at will.
Process Of Welding.
When the flash powder is fired there is
a binding sizzle in the crucible and the
iron oxide is turned into molten metallic
iron. The melted mixture is poured into
the hole in the mold around the pipe and
instantly raises the ends Of the pipe to
a welding heat. The wise is then screwed
up and the ends of the pipe crowded to-
gether about one-quarter of an inch. Then
the iron mold is knocked off. There is a
jacket of metallic iron around the place
where the weld was made and this, too, Is
knocked off. The pipe shows no sign of
a break at all and is really stronger at
the joint than anywhere else because It
is a trifle thicker. The process takes
about four minutes.
The cost Of making welded joint this
way is about twice what 1t would be to
screw it together with a pipe coupling,
but 1t is said that a welded joint 10 more
trustworthy than a threaded joint for
underground work.
The refrigerating plant as a whole is
being made with view to lasting and
easy repair. Ammonia pipes underground
are particularly liable to leakage. and the
pipe in this instance is laid in an open
tile conduit. SO that it will not be gripped
by the earth with which the trench is
filled. Between the buildings there Is a
manhole. and here the pipe is given q
spiral turn to allow for expansion and
contraction. At intervals along the pipe
line there are open pipes running to the
surface of the ground, SO II leak de-
velops in the pipe line at any time its To-
cation can be ''smelled OUT and the re-
pair made.
The cold storage plant will supply
rooms in the bureau Of chemistry and in
all the laboratories where they are needed.
The temperatures will range from 40 de-
grees to zero.