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Member

Join Date: May 2011
Posts: 5

### Can API 620 be Used Instead of API 650 While Selecting Curd Angle

07/24/2012 7:32 AM

hi. can any one help me!!! My query is explained below

Can we use API 620 while selecting curb angle and API 650 for rest of the tank, because the tank im designing has internal pressure of 2.5 psi, though it can be done as per API 650, but by using reuired area formula in API 650 apendix F section 5, comes to be very lage around 350 inch square. even when i use double angle of 180X180X16, the actual area comes out to be very small as compared to required area. But when i use API 620 FORMULAS to calculated participating area of curb angle, the area comes out to be around 19 sq.inch, which i am able to satisfy by using 180X180X16. Though still nothing less than this size satisfies the required area. I even increased to slope from 1:16 to 1: 12

- should i use API 620 for curb angle selection only
- or is there other way to satusfy formulas or any other general practice

Pathfinder Tags: curb angle selection
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Guru

Join Date: Jun 2010
Posts: 540
#1

### Re: Can API 620 be Used Instead of API 650 While Selecting Curd Angle

07/24/2012 10:05 AM

Are you designing the tank to 620 or 650? In general, I'd say the answer is no - you can't pick and choose parts of multiple standards to design anything. If the standard you are using to design something refers to another standard, then it is incorporated by reference.

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#3

### Re: Can API 620 be Used Instead of API 650 While Selecting Curd Angle

07/25/2012 1:02 AM

thanks, so it means that i can use API 620 for selecting curb angle and use API 620 for the rest like shell thickness, roof bottom

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#4

### Re: Can API 620 be Used Instead of API 650 While Selecting Curd Angle

07/26/2012 3:33 AM

SORRY I MEANT API 620 FOR SELECTING CURB ANGLE AND API 650 FOR OTHERS

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#5

### Re: Can API 620 be Used Instead of API 650 While Selecting Curd Angle

07/26/2012 9:32 AM

What in my initial response gives you that impression? When you put a nameplate on this tank, what will it say? I don't have access to either standard. AND DO AWAY WITH THE CAPS!

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#6

### Re: Can API 620 be Used Instead of API 650 While Selecting Curd Angle

07/27/2012 9:40 AM

i got that impression from what you wrote "you can't pick and choose parts of multiple standards to design anything". i used api 620 for selecting curb angle, as i mentioned in my initial comment, but just want to know it is ok or not?, because i calculated shell thickness, as per 650, and api 650 gives less thickness compared to 620

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#7

### Re: Can API 620 be Used Instead of API 650 While Selecting Curd Angle

07/27/2012 10:32 AM

can't = cannot ≈ may not

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#8

### Re: Can API 620 be Used Instead of API 650 While Selecting Curd Angle

07/27/2012 5:41 PM

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#2

### Re: Can API 620 be Used Instead of API 650 While Selecting Curd Angle

07/24/2012 12:12 PM

API 650 covers flat bottom tanks, and 620 also covers flat as well as other shapes. 620 max design temp is 50 degrees F higher than the 200 degrees F of 650. 620 covers up to 15 psi internal and 650 up to 2.5 psi (appendix F becomes applicable in case of internal pressure). 650 is vertical tanks only, 620 is vert and horizontal.