DNV Equipment Categorization for Plate Heat Exchanger 1

[SHIoffshore]

Hi,

I have three plate type heat exchangers to be installed on the FPSO which have PROD(N) notation.
So, I need the DNV certification for these heat exchangers as per the DNV-OS-E201 but I have no idea about the equipment category which shall be applied for.

Followings are specifications for the heat exchangers.

1) Medium : Crude oil(side1), Cooling medium(side2)
Flow(kg/h) : 172425(side1)
Inlet P(barg) : 2.5~3.5(side1), 6(side2)
Oper. T(C) : 90/40(side1), 30/45(side2)

2) Medium : LP gas(side1), Cooling medium(side2)
Flow(kg/h) : 11638(side1)
Inlet P(barg) : 1(side1), 6(side2)
Oper. T(C) : 76~90/40(side1), 30/45(side2)

3) Medium : Seawater(side1), Cooling medium(side2)
Flow(kg/h) : 2257000(side1)
Inlet P(barg) : 3~6(side1), 6(side2)
Oper. T(C) : 2~20(side1), 45/30(side2)


Please advise me which category shall be applied for each heat exchanger among the Category IA, IB and II.

Thanks in advance.

 

[gr2vessels]

SHIoffshore,
As you might have already noticed, you gave us incomplete info on your exchangers. The first two exchangers would be class IB, for standard plate heat exchangers (like Alfa Laval or similar). All that depends on the type (unknown) of your cooling medium (looks like some water / glycol mixture). Also, depends on the type of plate exchanger you are using (welded, gasketted?). For the third exchanger I would use the same IB for the sake of equipment importance rather than safety only, however Class II is normally applicable for the "cooling medium" cooler.
Cheers,
gr2vessels

 

[SHIoffshore]

gr2vessels,
Thanks.
I'll give you additional information to clarify more detail.

Cooling medium is mixture of water and glycol(68%/32%)
The first and third exchangers are gasketted type and second one is full welded type.

I thought that the category will be decided based on the pressure and mass flow. That's why I didn't specify the type and fluid characteristics.

Could you show me a reference which describe how the category is decided?