High temperature/High pressure piping systems 2

[robinxie]

Hi, everyone,

Dose anyone can provide the rule of thumb or resources for:
1. arrangement and layout of high temperature/high pressure piping systems and supports.
2. piping support component selection.

Many thanks ahead.

 

[davefitz]

sure.

rule no. 1: subcontract the work to an experienced outfit that has done it before

rule no 2: regardless of their experience , assume they will foul up this particular job, so critically review every step of their design, fab, and construction of the project.

 

[friartuck]

Once you have sorted out the right materials i.e. flange and valve type, pressure rating of fittings etc, you need to look seriously at expansion control.
Most good expansion bellows manufacturers have details on how to bracket, guide and accomodate pipework expansion.

Natural expansion accomodation would entail for instance running pipe down a corridor and then crossing over to the other side. The 'L' shape will accomodate some expansion.
Where branches are taken off long runs, come off the main with a 'dog leg'. This allows the branch to flex and not become stressed.

Inevitably you will need some form of expansion bellows or loop with large systems so get a good expansion bellows manufacturer on board.

We use 'engineering appliances' in the UK but there are good companies worldwide

good luck

Friar Tuck of Sherwood

 

[CRG]

For a high temp/pressure steam line, use expansion bellows as a last resort. While these are often used in low pressure steam lines in commercial buildings for heating, they are used less frequently in high temp/pressure lines used in industrial facilities. From my perspective, I would not use an expansion bellows unless there was a space constraint problem that prohibited me from properly designing the pipe routing with adequate flexibility. Too often expansion bellows are used in place of knowledgeable engineering.

Follow Davefitz advice and sub this work out. If you intend to do this yourself, plan on spending about 120 hours understanding the relevant codes and calculation methodology. If the system is complex, computer software is almost a necessity. I would not recommend trying to use a program unless you have competent understanding of the relevant piping code and its application.

If you gave a little more information about the actual pressure, temperature, and application, you might receive advice that may be more helpful. Is this indeed a high pressure/temp steam line?

If this is a B31.3 design, there are specific qualifications of the designer required to meet the minimum code requirement. I do not think that B31.1 has the minimum qualifications requirement for the designer; however, I believe that the B31.3 requirements seem reasonable for B31.1 designers as well.

Lastly, if you talk to a bellows manufacturer about using there products, remember that they earn their living selling bellows. Often, salesmen get paid on a commission basis for sales made. This makes their advice extremely biased and sometimes dangerous.

 

[DSB123]

CRG,
120 hours to understand the relevant codes and calculation methodology is a little light. There are those whom have been doing this for far longer and still do not know the ins and outs of the Codes. Stress calculation of pipework cannot be learnt in a short period especially for high temperature/pressure systems.

 

[CRG]

DSB123,

You are correct. I did not intend imply that after 120 hours of intensive studying, an engineer could be an experienced expert. In contrast, after a substantial investment of time spent researching the relevant codes, one only is at a starting place. The inexperienced engineer should work under an experienced engineer. That is why I referenced the qualifications of the designer/engineer two paragraphs down discussing the designer/engineer’s minimum qualifications.