5 replies to this topic

[Padmakar Katre]

Dear All ,
I have a basic question regarding the design pressure of the plate and frame in case of the Plate heat exchanger.The design pressure of the plates in PHE will be the max design pressure of either hot side or cold side whichever is the max.But can we have the design pressure of the Frames lower than the design pressure of the plates or different for cold and hot side frames either way.If the operating pressure of hot side is 8 Kg/cm2g and cold side 6 kg/cm2g and design pressure of the plates is 15.3 Kg/cm2g.Now the design pressure of the cold side frame is 15.3 kg/cm2g and the hot side is 14 kg/cm2g.Is this aceptable or should I have the same design pressure of both frames.
Thanks in advance for your reply.

Regards,
Padmakar Katre

[JEBradley]

To be quite honest im not quite sure what you mean by the frame design pressure here. (Im probably embarassing myself now) but from what I think of as the frame - its design pressure is going to be well above the plates. Is it possible you're considering a shell and plate??

Back to the question - you will need to relate your design pressure to the highest operating pressure. I suppose its the differential pressure really but at some stage one side will run empty giving a differential pressure equal to the full pressure of the highest pressure stream.

I think the design pressures you have are acceptable.

Nota Bene - I have about 3 years experience working in design and plant commissioning. I think you need to consider this in my posts - Im not as authoritative on the subjects as Art, Phil, Joe etc. (Im just saying - what ive written is comment only)

[pleckner]

You should be treating the entire plate & frame as a single unit when it comes to deisgn conditions.

[Chris Haslego]

In plate heat exchangers, the frame components are almost always the limiting factor in determining the design pressure. According to the ASME code, only the carbon steel plates and the large tightening bolts are considered pressure retaining parts. The heat transfer flow channels can typically withstand higher pressures than the frame (even though they're very thin) because the contact points between the plates add substantial rigidity.

For example, 0.50 mm, 316 SS heat transfer plates can be rated for full vacuum to about 170 psig according to ASME, while the frame that these plates are usually hung in will only be rated for a standard 100 or 150 psig.

Since compact heat transfer is one of my favorite topics, I'll be bringing more information on this topic to the site in the coming months.

[Padmakar Katre]

Dear All,
Thanks for your replies and sharing your thoughts.Dear Chris Haslego I am desperately waiting to see this information posted on the website.

Thanks and Regards,
Padmakar Katre

[JEBradley]

To add my voice of support - this information is eagerly anticipated