Dear all

I would like to know, can we use ASME SEC VIII DIV 2 for vessel with 500 degree cel. Design Temp? As, allowable stress for Bolting above approximate 430 degree celc. is not mentioned in SEC II-D for SEC VIII DIV-2.

Is it means that SEC VIII DIV-2 vessel can't be constructed for high temp.(above 430 degree cel.)?
furthermore, if no than why Table 5A (allowable stress for plate, forging, fitting) is given up to range 500 degree celc.

With regards
vishal Tailor

Hello Vishal

SA 193 B7 bolting can operate above 500C. ASME Section VIII, Division 2 does not have a particular restriction on the temperature. It all depends on the materials you choose for the construction. All materials have a temperature limit. Some are higher that others.

Dear Mr. Ray

Pl. note ASME SEC VIII DIV-2 is very particular about material allowable stress. DIV-2 have strict guide line & limit of Maximum permitted temp. Pl. refer ASME SEC VIII DIV-2 ANNEX 3.A clause no. 3.A.2, which describe allowable stress for Bolting. as per this clause Table 3 & Table 4 to be followed for Bolting allowable stress for Vessel designed as per Part 4 & PArt 5 respectively. Now, if we refer Table 3 & Table 4, Code has given Maximum temperature limit, where NO Bolting Material has Max Temp limit higher than 800 Degree F for Div-2 equipment

pl. reply

With regards
Vishal Tailor

Hello Vishal

This is from Annex 3.A.2:


3.A.2 Allowable Stress Basis – Bolting Materials
3.A.2.1 The materials that may be used in this Division for bolting are shown below.
a) Ferrous Bolting Materials for Design in Accordance With Part 4 of this Division – Table 3.A.8
b) Aluminum Alloy and Copper Alloy Bolting Materials for Design in Accordance With Part 4 of this Division
– Table 3.A.9
c) Nickel and Nickel Alloy Bolting Materials Bolting Materials for Design in Accordance With Part 4 of this
Division – Table 3.A.10
d) Bolting Materials for Design in Accordance With Part 5 of this Division – Table 3.A.11

I do not see a reference to temperature. Perhaps I am looking in the wrong place. I have also looked at Table 3.A-8. It is not there either. I am not saying that you are wrong, just that I cannot see the restriction on temperature in Annex 3.A.

Dear Mr. Ray
Pl. refer 3.A.2 thoroughly, you have covered half section only, please read 3.A.2.2.

For you information : ALLOWABLE STRESS CAN'T BE FOUND IN CODE OF CONSTRUCTION. SECTION II PART D SHALL BE FOLLOWED.

Hello Visha

Simple question: What does ASME Section II - Part D say for the material you have in mind?

Dear Mr. Ray
It's not as simple as it's seems too. Pl refer detail description of my question.
1. As per SEC II Part - D, Maximum Permitted Bolting Temperature is 430 Degree Celc. for SEC VIII Div-2.
2. However, as per SEC II Part-D, Low Alloy Steel Plate & Forging is permitted unto 650 Degree Celc for SEC VIII Div-2.

This means,Bolting Flange & other Bolting Connection is not permitted for SEC VIII Div-2 vessel above Design temp. 430 Degree Celc.

Now, Normally Every Pressure Vessel has Bolted Flange.

My Question is :
A)If, Bolting Flange is not permitted, it means, Vessel with Bolted construction is not permitted. Therefore, it interprets that Vessel is not permitted.
B)Then Why Plate & Forging Allowable stress is given upto 650 Degree celc.

Pl. Furnish experts comment.

With regards
Vishal Tailor [b][/b]

Hello Vishal

An ASME committee somewhere sets the limitations for the various materials. We have to work within those limits. The question of why, should be aaked of ASME. I cannot provide an answer as I have no authority to work outside the constraints of the code.