45 degree reinforcement ring
45 degree reinforcement ring
(OP)
Hallo guys,
I am a new fish here and also for the pipe stress analysis.
I am busy with a new project which contains lots of 45 degree reinforcement connections. The transport medium is HC Gas. We use Ple4win for the pipe analysis but it's impossible in the program to give a more than 5 degree tee connection.
there is also no equation in ASME B31.8. Is there a way to get the stress in those connections?
Regards
peipei
I am a new fish here and also for the pipe stress analysis.
I am busy with a new project which contains lots of 45 degree reinforcement connections. The transport medium is HC Gas. We use Ple4win for the pipe analysis but it's impossible in the program to give a more than 5 degree tee connection.
there is also no equation in ASME B31.8. Is there a way to get the stress in those connections?
Regards
peipei





RE: 45 degree reinforcement ring
I guess it's the stress intensification factor for a lateral tee that you are looking for. The only Code I know of that addresses this is the French Codeti, which takes the sif for a 90 degree connection and increases it by dividing it by {sin(angle)}^(3/2).
RE: 45 degree reinforcement ring
thans for your information, i will try to figure out firstly how SIF works in Ple4win for tees, then i will try the french code.
RE: 45 degree reinforcement ring
for tee stuk, SIF has out-plane and in-plane, how are these two factors influence the stress?
For example,
SEOT=Sqr(SXIT^2+SFIT^2-SXIT*SFIT+3TZUT^2), just multiply the factor with the detail stress?
Regards
peipei
RE: 45 degree reinforcement ring
RE: 45 degree reinforcement ring
What is the Operating Pressure?
What is the Operating Temperature?
Is this a Flare Heater?
Is this a sustained temperature or only an occasional excursion?
What is the Material?
What is the Header Size?
What is the Branch Size?
Where is the Anchor on the main Header relative to the Branch line?
What is the distance on the Branch lines before a lateral restraint?
You see, there is more to the question than you have shared with us.
RE: 45 degree reinforcement ring
Yes, the configuration for the gas statio is really big. And we don't use fine element program.So i guess the calculation is quite concept in the program i use.
the operating pressure is 7 bar, operating temprature is different from mainleiding and branch leiding. The material is also specific according to the drawing. So i just pick one 45 degree tee as an example.
Run: 24'' ASTM A106 GR B SMLESS SCH.40
Branch: 8'' ASTM A106 GRB SMLESS SCH.40
Pressure: 7 bar
Temperature:
Run: -65/+38
Branch: -20/+50
By the way, how to combine SIF-in plane and SIF-out plane if only i have to input only one SIF?
RE: 45 degree reinforcement ring
Second best method is to have oval repads made to fully reinforce the holes. The calculation on this is straightforward -- the area of the repad has to 'replace' the missing area of the pipe caused by the hole you cut.
RE: 45 degree reinforcement ring
Which standard has this regulation? Could you tell me?
RE: 45 degree reinforcement ring
I do not know of any 'middle ground' between these two methods, and a full FEA.
I'll bet that your pipe stress analysis program only looks at the external [bending] stresses and is missing the internal pressure stress. Pressure is the 'main event'. If your line splits open during hydro, nothing else matters. External stress can be dealt with using good supports and properly located pipe-guides and pipe-anchors.
RE: 45 degree reinforcement ring
I am really not familiar with American codes, most of the cases we use Nederlandse Code. And the program is also according to NEN.
So it is the first time that i search the ASME B31.3....
Anyway i will take a look.
The program has a combination calculation with and without pressure.
RE: 45 degree reinforcement ring
Just my opinion from where I stand. Please feel free to chime in with your observations.
RE: 45 degree reinforcement ring
http://www.bonneyforge.com/resources/BC.pdf
RE: 45 degree reinforcement ring
I don´t know any.
There is a code EN13480, but Dutch?
You don´t have to do everything acc. codes,
there is something like mechanical calc.s too.
Greetings from a countryman.
RE: 45 degree reinforcement ring
In this case, i will take a deep look at ASME, in previous case i only search the material specification.
To europipe,
we do have the EN13480(English) but i do not use too often.
The NL code is NEN serie, for example NEN-3650 & 3651.
RE: 45 degree reinforcement ring
RE: 45 degree reinforcement ring
RE: 45 degree reinforcement ring
I only calculate the stress according to the given configuration. It's our client who design the pipe.
and I am also worry about that the 45 degree connection will give me a lot of trouble.
RE: 45 degree reinforcement ring
IMO, if you are trying to pick a code and then control the stresses, you should inform your client about your code and if your client's designed connection is (is not) as per this code requirements. It is not only about the physic of this connection but the consistency of the design and more important the liabilities.
RE: 45 degree reinforcement ring
But when it was designed the temp is -20 degree but now they are going to lower it to -65 degree, that's why we have to control.