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Plate heat exchangers dismantling for inspection

02/12/2022 11:36 PM

Query for plate heat exchangers; is it required to dismantling for inspection, or cleaning in-situ is enough? what is the frequency of dismantling the plate heat exchangers?

In case of CRA material MOC, such as Titanium; it is expensive to open the plate HEX as the cost of the material is high. so what is the frequency of dismantling the HEX.

other query, is there any paper or code for inspection of plate heat exchanger

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#1

Re: Plate heat exchangers dismantling for inspection

02/13/2022 12:44 AM

Cleaning in situ is the preferred method of cleaning, but sometimes it's not enough, this is determined by pressure drop across the exchanger...

https://academy.paulmueller.com/good-maintenance-habits-for-plate-heat-exchangers

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#2
In reply to #1

Re: Plate heat exchangers dismantling for inspection

02/13/2022 12:56 AM

how about the based on the operation performance/ deficiency, based on operation call we will ask for dismantling.

appreciate your reply and thanks for the link

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#3
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Re: Plate heat exchangers dismantling for inspection

02/13/2022 8:19 AM

You should have and maintain a maintenance log that contains the temperature and pressure drop across the exchanger as well as other collected data that catalogs the maintenance and performance of the system, the in situ cleaning should be logged and the results noted as satisfactory or further cleaning necessary,,,,the maintenance interval should be recommended by the manufacturer and fine tuned by the head engineer....this will vary according to process and environment....if it becomes necessary to open the exchanger you should have all spare parts needed at hand...It's important to have a history of the temperatures and pressures so that it can be determined when scaling buildup is occurring and cleaning becomes prudent...

We used to check our equipment on a daily basis and make note of everything, any repairs are noted and cataloged as well as source information for parts including principals and contacts involved, prices, inventory on hand etc...a logbook should be kept in the same place all the time, our daily readings were hung directly on the equipment, and historical data was located in the maintenance office, with a drawer marked exclusively for maintenance records...

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#4

Re: Plate heat exchangers dismantling for inspection

02/13/2022 9:14 PM

Sanitary inspection yes,…

If there’s contaminates detected, yes,

What you need are spare gaskets, and if there is contamination, be prepared to replace plates. Also have the assemble schematic to put the plates back in the right order…

also be prepared to wash and scrub the plates if fouled…

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#5

Re: Plate heat exchangers dismantling for inspection

02/14/2022 3:31 AM

It is <...required...> if the maintenance regime, which will be facility- and process-specific, says so.

Cleaning-in-situ might be enough, however it is determined by process conditions rather than anything else.

The frequency of dismantling will be based on the effectiveness of the cleaning-in-situ regime, which is process-specific.

One always needs to schedule sufficient time for planned preventative maintenance, otherwise the plant itself will schedule breakdown maintenance instead.

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#11
In reply to #5

Re: Plate heat exchangers dismantling for inspection

02/15/2022 11:18 PM

"One always needs to schedule sufficient time for planned preventative maintenance, otherwise the plant itself will schedule breakdown maintenance instead."

This fundamental truth is cause for a "Good Answer"

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#6

Re: Plate heat exchangers dismantling for inspection

02/14/2022 6:35 AM

thanks everyone for your comments, appreciate..

any API Standards? or other standards? we are working in oil and gas industry.

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#7
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Re: Plate heat exchangers dismantling for inspection

02/14/2022 11:29 AM

Given that the maintenance is process-specific, and no two installations and no two processes are identical, the best place to look for these is in the maintenance areas of the facilities in question. After all, no-one knows better than the <...we...> working in those facilities.

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#8

Re: Plate heat exchangers dismantling for inspection

02/15/2022 12:10 AM

thank you alot for your input.

In cleaning in situ done and the maintenance team follow the instructions from the manufacture, then the HEX inspection freq. to be 3 years from integrity side or can be higher?

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#9
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Re: Plate heat exchangers dismantling for inspection

02/15/2022 2:55 AM

The answer is in the question: <... the maintenance team follow the instructions from the manufacture[r]...>. It can be either more or less frequent depending upon the process-specific criteria that the maintenance regime predicts.

The question is unanswerable as far as this forum is concerned. After all, the only individual that is likely to have access to all the information required is the Original Poster.

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#10

Re: Plate heat exchangers dismantling for inspection

02/15/2022 5:32 AM

SolarEagle gave a good answer so I'll just add a few things.

The usual method is in-situ (we call it CIP or Cleaning-In-Place). Keep a record of the pressure drop across the exchanger and if it starts to show an increase, it's time to schedule a shutdown for dismantling. You can also monitor temperature but I prefer to monitor the control valve (CV) position. Since the controller will try to maintain the temperature by changing the CV position, there will be no apparent temperature change but the control valve position will start to change.

For example: previously, the CV is at 50% to maintain 100ºC. After a few months, the CV is now at 60% but still maintaining 100ºC. That shows you that the HE's efficiency is starting to drop. You decide how much change will trigger a major cleaning.

Then, from your records, you can determine how long it takes before you need to dismantle the HE. You then work out your long shutdowns so that the dismantling coincides with your shutdown schedules.

regards,

Vulcan

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