Is rubber seal needed to assemble plate heat exchanger

[aaronmaoeric]

Hi, I found the instruction of remove plate heat exchanger says to remove 4 rubber seals, but don't find any, can somebody if I can wash and assemble plate heat exchanger without rubber sea?
Thanks in advance!

 

[cross thread]

All the plates I have removed have had a seal

 

[aaronmaoeric]

Thanks Mate, yes I found them on rail assembly, now another issue, when I assemble plate heat exchanger back, there is always water leak form right part(exchanger), even I think screw is secured, any comment?