TLV COS-16, Instruction Manual

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172-65175MA-13 (COS Pressure Reducing Valve) 16 Feb 2022
26
Problem Symptom Cause Remedy
The secondary
pressure
cannot be
adjusted or
increases
abnormally
(continued) Adjustment is
difficult, and set
pressure varies Flow rate exceeds rated
flow rate Check the flow rate,
replace with a larger size
The adjustment screw
has seized Replace with a new
adjustment screw
The small hole on the
piston is clogged Clean
Wear on piston ring Replace piston rings
The diaphragm is
distorted or damaged Replace with a new
diaphragm
There is fluctuation in
steam consumption Check the flow rate,
replace the COS if
necessary
The selected model is
inappropriate for the
service conditions
(specifications) Check the model
selection, replace the
COS if necessary
Upon closing the
valves on the
secondary side,
the secondary
pressure abruptly
rises as high as
the primary
pressure The bypass valve is
leaking Check, clean, and
replace with a new valve
if necessary
There is a build-up of dirt
on or damage to the pilot
valve seat or main valve
seat Clean
Align
Replace if necessary
Hunting or
chattering
occurs Occurs at low
steam demand It is being operated below
the lower flow rate limit Check the volume of
steam supply, replace
with a smaller diameter
valve
Hunting never
stops There is too high a
reduction ratio (operated
at below 10% of the
primary pressure) Use a two-stage
reduction arrangement
The selected model is
inappropriate for the
service conditions
(specifications) Check the model
selection, replace the
COS if necessary
Chattering never
stops Condensate is contained,
or the trap is blocked Check the trap
Check the piping
The selected model is
inappropriate for the
service conditions
(specifications) Check the model
selection, replace the
COS if necessary
Abnormal
noises Makes a high-
pitched noise There is too high a
reduction ratio Use two-stage reduction
The flow is too great Check the flow rate and
use a larger size valve
There is a high-speed
open/close valve nearby Install the valve as far
away as possible
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