Raco Ball & ACME screw Electric Actuators cover a broad
range of applications, are environmentally friendly, robust
& low maintenance replacements for hydraulic/pneumatic
cylinders. The modular systems design allows for Straight/Right-Angle/C-Design variations. Thrust up to 225,000 lbs, speeds up
to 30”/sec, strokes up to 20 feet. For fast linear movements up
to 400”/sec RACO produces the belt driven LM-Actuator. X-Y-Z
arrangement can be easily designed for paint/cutting/sorting/
parts, such as liquid
processes go into
making valve parts,
finish of a valve
stem, ion nitriding
of a valve cage,
honing, the use of
vacuum furnaces to
reduce oxidation, heat treating, etc. Unless the counterfeiter
has access to OEM design documentation, the machinists
have no idea of the processes the valve manufacturer used
to make a part, making it impossible to produce a perfectly
Five of the leading failure issues caused by problems in
counterfeit valve parts include:
1. Poor control around setpoint: Friction is the enemy
of good control. Every valve manufacturer designs
parts with very tight tolerances to minimize friction.
Increased friction makes a valve harder to operate,
and can result in a valve actuator no longer able to
position the valve to the setpoint.
2. Reduced service life: Higher friction can quickly lead
to increased wear and lower service life. It’s common
for a valve manufacturer to harden mating or trim
parts to increase their service life. Counterfeiters
may not—and usually don’t—have access to the
specifications for overlays and other critical processes
for reducing friction.
3. Galling of metal: If a valve is installed in a process
that requires hardened trim, but the replicator doesn’t
harden the parts, the parts can wear down, gall the
surface, and eventually fail.
4. Leaks: Leaks through the packing or flanges due to
substandard parts can cause operational waste, process
control, safety, and OSHA or EPA issues. Stem finish
relates to packing life and leakage. Emerson engineers
measured the AARH on a counterfeit valve stem that
failed: the replicated part measured 11 times rougher
than the Fisher valve part.
5. Valve failure: A complete failure is rare, but can
happen when a counterfeiter does not have the product
expertise to understand design limitations.
Most process plants have dozens if not hundreds of
control valves. Each of these valves requires ongoing
maintenance because there are many moving parts, and
many plants are tempted to use counterfeit parts, thinking
they are saving money.
But while counterfeit parts may work in some cases, the
parts are not equivalent to parts from the original valve
manufacturer. Using substandard parts can cause problems,
and the anticipated savings can quickly result in downtime,
higher maintenance costs, and decreased safety.
Karl Lanes is senior director of global parts at Emerson
Automation Solutions in Marshalltown, IA.
Figure 2: A PMI gun can identify
the alloy being used in a valve
part. Here, it is analyzing the
valve body of
a Fisher valve.
Figure 3: These
parts were not
trim galled and
the plug stuck
in the seat.