My Company rents oilfield equipment, and we had a
flange X union adapter come apart during a manifold hydro test. It failed
in such a way that it appeared to simply break in two, right in the
middle, where it appeared to be welded together. Fortunately no one was
hurt, but I have been charged with making sure we remove all of the units
we own that may be likely to fail.
How would you suggest I should go about this task?
We suggest you investigate to find
if your company has files that include Material Test Reports and
test records on your inventory items. If you find these, you can probably
have confidence in the equipment so documented.
At this time (2016),
manufacturers that make these equipment units having smaller flanges,
usually make them from one piece of steel, either bar stock or a
Since you had a welded unit fail,
for those items for which you can find no documentation, you may want
to sort them; as those that appear to be made as one piece, and those that
appear to have welded assembly.
Below you will find attached a
drawing that displays the general appearance of a Flange X Union Adapter
"Made Without Welding" and as "Made by Welding."
So that no misunderstanding may
exist, "Made Without Welding" means the part does not include welding as
an assembly step. Welding may always come into play for cladding,
overlay, inlay, and repair welding necessary because of field damage.
If you want to remove from your
inventory, any Flange X Union Adapters that you believe assembled by
welding, I suggest you would do well by simply following two rules.
First, remove all units obviously welded together (meaning you can
visually see the fabrication weld). Second, remove any units that look
sufficiently different from the drawing "Made Without Welding" below, that fabrication
by welding best explains the difference in appearance. These two steps
may miss some welded units, and may result in your discarding some units
made without welding, but the small number of errors using this criteria
should have little cost in the larger scheme of things.
Note: Adapters having
large flanges with much smaller union halves attached, usually have
welded assembly because of the cost to manufacture them in one piece. If
their appearance seems satisfactory, you should test these units and
retain them if they pass the test.
In any case, all of the
units you wish to keep in your inventory for which you have no
documentation that certifies a hydro test, should have a hydro test,
documented and tied to your inventory records. If any units fail on
test, discard the pieces.
UNITS WITH MALE HALF UNION MADE WITHOUT WELDING MUST HAVE
REMOVABLE NUTS WITH SEGMENTS AND RETAINER RING
UNITS MADE BY WELDING WITH
MALE HALF UNION MAY HAVE A NON-REMOVABLE NUT
Caution: When tightening Hammer Unions, always wear safety glasses.
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