SOLAR RADIATION

[PIPING3984]

I want to know the Pipe stress analysis temperature due to sun solar radiation?I would appeciate it if you guys out there could help me in answering this.

 

[BigInch]

I've used up to 70ºC for exposed piping in some severe desert climates, but I wouldn't think anything over 50ºC would be needed for most locations.

http://virtualpipeline.spaces.msn.com

 

[PIPING3984]

THANKS BigInch FOR THE IMMEDIATE REPLY .

 

[BigInch]

Woke up early again.

But with "global warming", 70ºC might be appropriate for everywhere these days.

http://virtualpipeline.spaces.msn.com

 

[C2it]

I have used 80 deg C for solar in some Saudi work. Usually it will be defined based on expereience, in Project Design Basis documents.

 

[BigInch]

80 is pretty high. Saudi Aramco spec is usually only around 55ºC for exposed elevated white painted pipe. Was it black?

http://virtualpipeline.spaces.msn.com

 

[C2it]

BigInch,

Not sure of the colour ... yellow in the CAD model from memory (!) I think it was silver grey in the field.

 

[BigInch]

Model must have been about 600ºC then.

http://virtualpipeline.spaces.msn.com

 

[PIPING3984]

I would like to know , What is the difference between "Design Pressure" and "Maximum Allowable Working Pressure" (MAWP)?

 

[C2it]

You should really start a new thread with this question. Check the codes ... B31.3, ASME VIII etc for a word perfect definition.

 

[BigInch]

In most codes, a "design pressure" is effectively what you use for engineering and design. Test (typically a hydrotest) pressure is the design pressure x the test factor. Maximum allowable working pressure (or maximum allowable operating pressure)is an/the actual test pressure divided by the test factor. MAWP, or MAOP takes precedence over the design pressure value.

http://virtualpipeline.spaces.msn.com

 

[PIPING3984]

Then what is ACTUAL test pressure ?

 

[BigInch]

You know, its the minimum pressure registered and held (according to a certified test gage) during the specified time period of the (hydro)test of the component in question.

http://virtualpipeline.spaces.msn.com

 

[NozzleTwister]

Back to Solar Radiation Temperatures.......

I'm currently working on a project in offshore Norway and the client has asked us to use NORSOK Standard L-002. In that standard, they tell you to use an installation temp. of 4 deg. C and use 60 deg. C for solar radition for exposed piping.

A Caribbean client mandated we use 170 deg. F (76.7 deg. C) for solar radiation.

On most jobs we see 140 deg. F (60 deg C) or 150 deg. F (65.6 deg. C)

NozzleTwister
Houston, Texas