"Overtightening plate heat exchangers/failure to seal?"

[Andrew Carr]

Anybody ever had problems with 

"Overtightening plate heat exchangers/failure to seal?"

[Skye Ferguson]

Some of them warp if overtightened. They warp around the fastener holes and the mating surfaces cannot draw evenly. 

I saw it happen on a set that was not overtightened but was torqued to spec without “staging” the torquing. 

So we learned to tighten, let sit for 24 hrs, torque low end, let sit for a shift or so, then torque final. 

Bolt on hatch covers sometimes do that if you don’t give the cloth inserted neoprene gasket material some time to release before going gangbusters with an impact. 

Old school guys know what "bunny butts” are for in the case of weeping around fasteners. 

I think the politically correct term used is to call them "cloth grommets" nowadays. (I do not recommend anyone searching for that first term on google.) 

Its a quick fix on hatch covers but I don’t think there is an easy fix on plate heat exchangers, at least not one I know of.

R/

Skye Ferguson
Marine Engineer
220 Spring Street, Suite #500
Herndon, Virginia 20170
Cell: 540-305-7959

On Feb 1, 2021, at 9:36 AM, Andrew Carr <carr.a...@gmail.com> wrote:

CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.

Anybody ever had problems with 

"Overtightening plate heat exchangers/failure to seal?"

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[Larry Miles]

Depends on the plates gasket style.   Plate stack thickness is critical upon completion.  Need to know that dimension and measure to ensure stack is same all the way around periphery upon completion.  Also need to compress evenly as you get to that final thickness.  

Mistakes are easy to make - gasket out of place, debris across gasket, plate in with wrong orientation, break in gasket, uneven application of compression, etc.  

Larry Miles, Port Engineer  Crowley Shipping | Petroleum Services I Engineering o 206.332.8047 | m 206.399.1011  Larry...@crowley.com

 

On Feb 1, 2021, at 9:01 AM, 'Skye Ferguson' via West Coast Port Engineers <westcoas...@googlegroups.com> wrote:

 Some of them warp if overtightened. They warp around the fastener holes and the mating surfaces cannot draw evenly. 

I saw it happen on a set that was not overtightened but was torqued to spec without “staging” the torquing. 

So we learned to tighten, let sit for 24 hrs, torque low end, let sit for a shift or so, then torque final. 

Bolt on hatch covers sometimes do that if you don’t give the cloth inserted neoprene gasket material some time to release before going gangbusters with an impact. 

Old school guys know what "bunny butts” are for in the case of weeping around fasteners. 

I think the politically correct term used is to call them "cloth grommets" nowadays. (I do not recommend anyone searching for that first term on google.) 

Its a quick fix on hatch covers but I don’t think there is an easy fix on plate heat exchangers, at least not one I know of.

R/

Skye Ferguson
Marine Engineer
220 Spring Street, Suite #500
Herndon, Virginia 20170
Cell: 540-305-7959

<unknown.tiff>

On Feb 1, 2021, at 9:36 AM, Andrew Carr <carr.a...@gmail.com> wrote:

CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.

Anybody ever had problems with 

"Overtightening plate heat exchangers/failure to seal?"

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<unknown.tiff>

[Marcus Alden]

Sorry....I had to bust out laughing at this question.....misery loves company.

Years ago, DNV required us to open up our main engine oil cooler for inspection. This is an exchanger that has jacket cooling water on one side and engine oil on the other...fought like hell to not do this as warping, gasket placement etc will create a FUBAR situation.

It took 2 sets of gaskets and several new plates to get it sealed.....the boat left to get to Dutch for the fishing season (late)....about 5hrs  into the voyage in the straights of Juan de Fuca, the cooler blew up....FUBAR....thanks DNV!

And more to the point...plates are wonderful but fickle beasts......over/under tightening, warping are true issues.

Good luck

Wash your damn hands!

Quit touching your face!