Hello, this is VALVEPARK.
Today we will share a valve leakage case food cold-storage linethat occurred on the
at Company C's logistics center in Ulsan.
If you have ever run into this kind of situation, be sure to read through to the end.
We will walk through the cause and the resolution in detail.
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Site: Company C's logistics center in Ulsan
Facility: food cold-storage line
Product: Control Valve
Symptom: fluid leakage exceeding the allowable limit even with the valve closed.
[DOWVALVE] Pneumatic Globe Control Valve (A216-WCB/150#)
Pneumatic Globe Control Valve E/P POSITIONER: TS-600L(IP-66) AIR FILTER REGULATOR: TS-300
www.valvepark.com
The valve in use was a 2-inch Control Valve (300#, CF8); leakage was found on 1 out of 3 units.
When we inspected the site, the core issue was that the valve was not closing completely.
Q. Why was that?
A. It came down to the positioner mounted right next to the valve.
The positioner is the device that controls how far the valve opens.
0% = fully closed
50% = half open
100% = fully open
That is how it is regulated.
The on-site inspection showed it was not a structural defect of the valve itself,
but rather a positioner setting fault that prevented the valve from closing completely.
The exact reason the Zero Setting drifted is not certain, but the following possibilities were identified.
✓ Impact during valve installation or transport caused the positioner setting to drift
✓ Vibration during operation caused the setting to drift
Takeaway
Recognize that Zero and Span values can drift at any time after valve installation,
and always recalibrate Zero and Span once installation is complete.
Periodic positioner calibration must be carried out.
We resolved the issue on this valve through the following procedure.
1. Recalibrated the positioner Zero Setting on site
2. Tests confirmed the fluid leakage was completely eliminated
✔ After the fix, all valves were confirmed to operate normally upon restart
We recommended several measures to prevent the same issue from recurring.
1. When setting up the positioner, perform Zero/Span calibration and a stroke test
2. Check the alignment between the positioner and the actuator
3. Establish a Standard Operating Procedure (SOP) for periodic calibration after installation
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👨🔧🔍
This leakage issue was caused by a closing fault stemming from a Zero Setting error in the valve positioner,
and was resolved immediately through recalibration.
To prevent similar issues in the future,
always perform Zero/Span calibration and a stroke test after valve installation,
and inspect the alignment between the positioner and the actuator.
It is also important to establish a standard installation SOP, strengthen operator training,
and maintain a regular calibration cycle (for example, every 6 months to 1 year).
In short, systematic precise calibration and routine inspection during installation and operation
are the surest way to prevent positioner setting drift.
We hope this case is useful for anyone running similar valve setups.
Accurate setup and proactive prevention can stop even the smallest leak.
We cannot emphasize it enough.
We will continue to share field-focused technical information and problem-solving cases.
Technical questions and related feedback are always welcome.
Thank you.
.
.
.
🏃♂️💨
For inquiries about control valves and other valve products, accessories, or maintenance,
visit the industrial valve specialty store, [VALVEPARK Store].
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