hydrotest pressure calculation as per PED

[mechyp]

I am trying to calculate hydro test for PED work.

Material are used for construction SA 350 Lf 2 CL 1,SA 420 WPL6, SA 516 GR 70
Design Tmp: 365 C
Design Pre: 7.5 bar (MAWP)

Per Annex 1 7.4 hydro is no less than

-1.43 x MAP (this is i understood)
but

-1.25 x MAP x LSR (Lowest stress ratio)- (stress form ASME Section-II part D- this is right ?)

So the consideration of MAT means multiply the ratio for stress between test and design temp right ?

PED allowable stresses (if so there are many possible ratio's dependent on the method that results in the lower stress value...per Annex 1 7.1

please correct if wrong.

yogesh

 

[XL83NL]

First of all, PED is sometimes vague on certain details, like the one you reffered to.
Remember that whenever a harmonized standard is used to design pressure equipment to comply with PED 97/23/EC (like e.g. EN 13445 for PV's), that standared inherently assures compliance to the PED (sometimes by means of annexes ZA, ZB, etc) and may provide more detail to the ESR (Essential Safety Requirements) as you mentioned.
It's also useful to review the PED Guidelines, e.g. guideline 8/2

Whats is your application? For B31.3 work I usually take a pipe spec that is flange limited and use a hdyropressure which 1.5 times the flange rating @ ambient temp.
That way I always satisfy the Code, and PED, where applicable.

However, other users here (SJones) may give you a better answer.

 

[C2it]

By definition, section 345 of ASME B31.3 requires a hydrotest pressure of 1.5 x (design pressure) x (Sc/Sh), but not exceeding yield stress.

 

[XL83NL]

ASME is not under review right now, Directive PED 97/23/EC is.

 

[smart143]

Lowest stress ratio is to be taken from design code, if its sec VIII Div I then ASME Section-II part D is to be refered & if its B31.3 then table -A is to refered from B31.3.
I hope it make sense now.

 

[smart143]

LSR (Lowest stress ratio)- is to be taken from design code, if yuor design code is sec VIII then sec II D applies & if its B31.3 then refer Table -A in B31.3.

Hope it make sense now.

 

[mechyp]

my vessels is ASME + PED