Troubleshooting - Yoshitake GD-26G Product Manual

4.5 Troubleshooting

Trouble
Reduced pressure
does not reach the
desired value.
Abnormal pressure
rises at the outlet
side.
Abnormal sound
Most of problems with the pressure reducing valve are caused by foreign substances and scale in
the piping. Avoid the ingress of dust and dirt to the product with caution.
A phenomenon similar to valve failure could occur due to the failure of the pressure gauge,
leakage or insufficient tightening of the globe valve in the by-pass line, clogging of the strainer,
and other causes. Check the above possible causes and take a proper remedy and preventive
measures.
Cause
1. The working pressure is improper.
2. The nominal size of the product is
too small for the flow rate for use.
3. Pressure adjustment is improper.
4. Strainer built in the product is
clogged.
5. Pressure gauge is broken.
1. Foreign substances stuck between
the disc [8] and the valve seat [3],
or scratch on them.
2. The O-ring [6] is damaged.
3. The diaphragm [9] is damaged.
4. There is a leakage from the globe
valve of the by-pass line.
1. The nominal size of the product is
too large for the specifications of
the system.
2. The pressure reduction ratio is too
large or the maximum pressure
difference is exceeded.
3. A quick operating valve is located
near the product.
1. Correct the working pressure. (See
"2.1 Specifications" .)
2. Replace the product with the proper
nominal size.
3. Readjust the pressure in accordance
with the given procedure.
4. Clean the strainer.
5. Replace pressure gauge.
1. Disassemble the product and
remove the foreign substances. If
scratch is observed on the valve
disc or valve seat, replace it.
2. Replace the O-ring.
3. Replace the diaphragm.
4. Repair or replace the globe valve.
1. Replace the product with the proper
nominal size.
2. Reduce pressure in two stages.
(See "2.1 Specifications".)
3. Keep a distance between them as
large as possible.
9
Remedy
■ EP D T-088■