This post is the continuation of the
"Disappointing New Plate Heat Exchanger” post.
After installing and using the new plate heat exchanger (PHE), we could not get the flow rate and temperature. This was really a problem because we were expecting the new PHE to perform excellently.
The PHE seems to be leaking although we have tightened it from 540mm to 529mm. The minimum length we can go according to the design is 506mm. But that is applicable after running the PHE after certain duration of time, not tightening it while it’s still new.
I called the PHE supplier and asked what’s wrong with the PHE? What should we do? Should we tightened it some more? The leaking is only at the end plate. Should we dismantle and check the end plate? Maybe the gasket is not evenly glued on the end plate? Maybe the gasket is damage or distorted!
The technical engineer came the following day and we performed an air test to show him the leaking points. He noticed the leaking point and agreed to dismantle the PHE to check what it wrong.
After dismantling the PHE, we found out that one plate is not arranged correctly. That was very surprising and it was not supposed to happen for a branded and reliable heat exchanger from Germany. Soon we found out that the heat exchanger was actually fixed locally by the supplier’s principal and not by the manufacturer in Germany.
The technical manager then guided our maintenance fitters to fix back the plate heat exchanger. Carefully they checked the plate’s arrangement. Diversion plates, flow pates and end plates must be in correct order. We don’t want to repeat the same mistake. If not, we are just going to waste our time and energy.
After completed fixing the PHE, we conducted air test and hold the pressure at 2 bars. We used soap liquid to check for any possible leakages. The pressure maintained for nearly one hour and that was good sign that the plate heat exchanger is not leaking.
We then gradually used the PHE and finally we get the desired temperature and flow rate. I’m so happy and glad that the new PHE is working perfectly as we plan. Now, we are focusing on other improvement and maintenance job such as cleaning in place (CIP), insulation, spare pipeline, and others. We’re taking it one by one.
Moral of the story:
1. Don’t expect a product or service to be perfect. Hope it to be perfect! If not, trouble shoot as soon as possible.
2. Be extra careful while arranging and dealing with plate heat exchanger. Once your arrangement is wrong, the entire effort is a waste.