MAINTENANCE & REPAIR
BY GREG JOHNSON
Protect Me Please
Everyone in the valve industry should be in the protection racket. No, I
don’t mean dealing with cousin Vito from
Jersey; I‘m talking about protecting
valves after they leave the plant for shipment to the customer or while they are in
storage waiting to be used. Valves that
are contaminated or damaged before
they are installed are a real problem that
costs the industry hundreds of thousands
of dollars every year to correct, either
through repair or replacement.
Every valve should be adequately
packaged and protected for shipment,
and every valve received by the user
should be well protected until it is time
for installation. As far as initial shipment, most valve manufacturers do a
good job of protecting their products.
There are dozens of types and styles of
protectors available to cover any end
configuration. These end protectors
serve two valuable purposes: The first is
to ensure dirt and debris stay out of the
bore of the valve, and the second is to
keep machined surfaces underneath the
valves from being damaged enroute or
during installation at the job site.
If valves are not blocked in crates for
shipment, they must be strapped to
skids or pallets in such a way that the
valves will not slide into the machined
areas of adjacent valves. Even with an
end protector attached, the mass of a
loose valve combined with transportation vibration can result in nasty
scratches on companion valves. If the
scratch is on a machined surface such
as a raised face, the cost to repair the
valve can reach hundreds of dollars or,
if alloy valves are involved, even more.
Here, the valves are correctly protected for shipment and short-term storage.
past the end connector. If moisture
remains in the valve for a period of
time, rust will develop that can damage
interior surfaces.
The biggest enemy of good valve care
is the infamous lay-down yard at construction sites. It sometimes seems like,
during the dark of night, mysterious
DAMAGE FROM WATER
Most end protectors are not waterproof,
and a pouring rain can penetrate
through virtually any small leak path
This is certainly the wrong way to store valves!
demons inhabit these places and randomly remove end covers from the
valves. Without this protection, the
sand, gravel, weld spatter and other
construction debris collects in the valve
ports. Then, unprotected serrations of
raised-face valves become rapidly rusted and lose their texture and geometry,
sometimes requiring expensive field
machining to restore integrity. Often-times valves will be stored horizontally
with one of the flanges flat on the
ground. This poor storage practice can
result in moisture being trapped in the
port and possibly additional mechanical
damage if the valve is dragged across
the gravel.
Valve stems are usually shipped lubricated. This lubrication is a magnet for
dirt and sand, which will ultimately act
abrasively on the stem and stem bushing.
Because of this, stems should be covered
with a protective wrapping, especially if
any sandblasting will be performed
upwind from the storage area.
If valves have been ordered in a
cleaned condition for special service
applications, extra care must be taken to
ensure their integrity. Bagged valves
should not be stored on bare pallets due
