23
Troubleshooting
NEVER apply direct heat to the float. The float may explode due to
increased internal pressure, causing accidents leading to serious injury
or damage to property and equipment.
WARNING
When disassembling or removing the product, wait until the internal
pressure equals atmospheric pressure and the surface of the product
has cooled to room temperature. Disassembling or removing the
product when it is hot or under pressure may lead to discharge of fluids,
causing burns, other injuries or damage.
CAUTION
When using this product, NEVER stand close to, or leave tools anywhere
near moving parts, such as the shaft. Contact with moving parts or objects
becoming caught in moving parts could lead to injury or damage or other
accidents.
CAUTION
This product is shipped after stringent checks and inspection and should perform its
intended function for a long period of time without failure. However, should there be
any problem encountered in the operation of the
PN-COS-16
, consult the
troubleshooting guide below.
Trouble could occur in the drive section, pressure-reducing section (including
separator and trap sections), or the controller used together with the
PN-COS-16
.
The location where the trouble has occured should be identified first.
<Diagnosis of malfunctions in the pressure-reducing section>
Problems are classified as follows:
1. The secondary pressure does not increase.
2. The secondary pressure cannot be adjusted or increases abnormally.
3. Hunting (fluctuation of the secondary pressure) occurs.
4. Chattering (a heavy mechanical noise) occurs.
5. Abnormal noises.
6. Steam leaks from the steam trap or condensate is not discharged.
Major causes for the above problems are usage under non-specified conditions (out of
specifications), insufficient pressure or flow rate, and clogs by dirt and scale.
Problem Symptom
Cause
Remedy
The
PN-COS-16
body is not warm
No steam is being
supplied or the valve at
the primary side is closed
Check the primary piping
and valves
The strainer at the primary
side or the separator
screens is clogged
Clean or blow down
The secondary
pressure does
not rise
The body is warm,
but the pressure
does not increase
No motive air is being
supplied
Check the motive air
supply line
The pilot screen is
clogged
Clean
The flow rate is too low
Check the flow rate; check
the model selection,
replace with a unit that has
a smaller nominal
diameter or a more
suitable unit if necessary
The secondary
pressure
cannot be
adjusted or
increases
abnormally
Adjustment is
difficult, and set
pressure varies
The piston is clogged with
dirt
Clean
Check the piston ring
Troubleshooting continued on the next page
172-65588MA-02 (
PN-COS
Pneumatic Control Valve) 5 Sep 2014
