HDPE Stub End Design in PE Lined Carbon Steel Spools for Oil & Energy

[ram0608]

Hi! We design HDPE Stubend(s) for use of HDPE Lined carbon steel pipelines application. We provide stubend collor thickness (flange face thickness) double of pipe thickness. In recent conversations, we came to knew stubend flange face thickness 1 to 1.5 times of pipe thickness is sufficient.

We would like to know what will be the idle flange face thickness or flange dimensions without effecting the application. (HDPE lined carbon steel pipelines or spools) Photo of HDPE Stubend attached for reference.

Also let us know what will be %of compression on HDPE flange face thickness during tightening.

Thanks in advance.

RAM

 

[BigInch]

Hire an engineer to get the answers you're looking for. This is a website to ask for tips to find out how to best proceed with the engineering work that YOU are doing, not a place to get free engineering done FOR YOU.

We will design everything from now on using only S.I. units ... except for the pipe diameter. Unk. British engineer

 

[jamesengineer]

Hi Ram

What pressure rating will the pipe have? Also what flange standard are you using PN10/16 etc etc?

This is my first post so am not sure how to (or even if you can) send a personnel message.

 

[ram0608]

Hi James,
Thansk for your response. The application is in PE pipelining for carbons steel spools. PE lining used as corression protection purpose. so, the pressure will be taken care by CS pipe and pressure varies from 30 bar to 100 bar based on application & CS pipe. Evnthough for design of liner pipe we consider collapse pressure, swell etc., generally the liner pipe SDR will be in between 17 to 11 - RAM

 

[jamesengineer]

Ram

If i'm understanding the application correctly then reducing the thickness of the stub flange will reduce the surface area which the pressure will be acting on that is not supported by the wall of the pipe.

If this is the case then surely reducing the thickness from 2 x wall thickness to 1 x wall thickness would offer an improvement in durability by reducing the shear stress at point X.

See attached.

"Two hands working can do more than a thousand clasped in prayer"

 

[stanier]

I investigated this matter many years ago with major manufacturers of PE stub flanges. Basically the industry didnt do any engineering design. Rather they relied upon samples and physical testing techniques. The testing techniques were quite rigorous and extensive because of the properties of PE.

If you want someone to analyse it for you I suggest you engage Paulin research. They may even be able to provide non linear solids modelling software. Alternative software would be from Algor ( now owned by Autodesk).

However FEA in the hands of novices is inviting danger. this is not an easy problem to solve as the PE has non linear properties related to temperature strain rate and duration, fatigue and time.

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

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