2 replies to this topic

[sanchit_11]

Dear All,

 

As per API 14 E different value of C is available with respect to quality of fluid viz., corrosive, sand content, intermittent, continuous, etc.

 

My query is that, will it be advisable to use same C values irrespective of type of piping material viz., GRE, CS, DSS, CU-Ni, SS, etc.

 

regards

Sanchit

 

 

[ankur2061]

Sanchit,

 

'C' value is indeed dependent on the material of construction of the pipe. However, these values have been established based on standard metallic pipes such as carbon steel, stainless steel and duplex stainless steel because the wall stress values for a given pipe schedule and nominal pipe size as per ASME B36.10/19 are well established for these metals.

 

To understand how 'C' value is calculated refer the attachment in the link below:

 

http://www.cheresour...acy-assessment/

 

Other elastomeric pipes such as GRE, HDPE etc. do not follow the nominal pipe size or schedule designation as per ASME B36.10/19 and hence there is no standard published data for wall stress and thus the the 'C' values. However it is important to note that due to the inherent lack of strength of plastic pipes in comparison to steel pipes, maximum velocities in plastic pipes are severely restricted. This has more to do with the reaction forces acting on the plastic pipe and weakening it due to high velocities rather than erosion. 

 

For Cu-Ni, Norsok standard - P001 restricts the maximum velocity for liquid service to 3 m/s.

 

For metallic pipes (CS/SS/DSS) the 'C' values can be referenced from the link below:

 

http://www.cheresour...per-api-rp-14e/

 

Hope this helps.

 

Regards,

Ankur.

Edited by ankur2061, 07 January 2014 - 07:21 AM.

[sanchit_11]

Thanks Sir,

 

Your answer is quite helpful for my knowledge enhancement.

 

regards

Sanchit