PankajMR
Materials
- Nov 7, 2015
- 1
I am seeking for a set of machines to decrease production cost and increase welding speed.
Description of the pipeline project is as follows:
Onshore Pipeline: API-5L- X65-PSL2, 56” Dia., 0.780” To 1.125” Wall Thicknesses.
Machines and welding procedure specifications should be capable to produce sound welds in 0 to 30% Slope of ground.
I will appreciate if you can help me with the following questions:
1- Which one is practical for production of a sound root bead? Internal welding machine (IWM) or internal clamp with copper shoes?Why?
Internal welding machine (IWM) has some advantages like higher speed of root welding, pipe lowering after root pass, better capability of welding in slope and better tolerance to Hi-low. But internal clamp with copper shoes is cheaper, easier to use and needs less maintenance. Thus I am eager to know if internal clamp with copper shoes is suitable for our onshore project or we must purchase an IWM?
2- According to API 5L standard maximum end out of roundness tolerance of normal pipes is 13 mm. While according to Annex J of API 5L standard, maximum end tolerance of out of roundness of offshore pipes is 10 mm. According to a specification (Prepared for Shell Canada Energy) maximum end out-of-roundness of offshore and onshore pipes should be 5 mm for automatic welding. In addition, tighter tolerances on pipe end out-of-roundness and internal diameter may apply to specific line pipes.
Which Criterion is acceptable and economical to purchase pipes (15, 10 or 5 mm)? Is tolerances less than 5 mm needed for welding root pass by copper backing ?
3- Some manufactures of internal line-up clamps (ILUC) offer strong clamps for automatic welding comparing to manual welding (like Serimax ILUC which needs112 bar pneumatic pressure supply & Hercules ILUC which applies 800 ton force).
Is there any calculation or experience for appropriate selection of “out of roundness tolerance and Internal Clamping force” to decrease Hi-Low to less than 1 mm?
4- Mechanical damage during shipping of pipes causes denting and ovalization. How damaged pipes can be repaired to acceptable tolerance of out of roundness? (Can mentioned high power internal line-up clamps (ILUC) reduce out of roundness for automatic welding?
5- Some manufacturers of pipe facing machines offer machines with high hydraulic pressure, for example Serimax Co. offers:
POWER SUPPLY REQUIREMENTS
Hydraulic Main: Flow: 225 to 340l/min
Pressure: 110 to 150 bar
Hydraulic Auxiliary: Flow: 15 to 24l/min
Pressure: 60/70bar – Maxi 110 bar.
Although some other machines with floating head cutters can produce reliable Narrow gaps which need less hydraulic pressure. Are floating head cutters necessary to produce sound welds? Which pressure range is appropriate for pipe facing machine?
Here are some paragraphs of mentioned line pipe specification (Prepared for Shell Canada Energy):
Modification of API 5L Standard:
Table 10 Modify as follows:
For all pipe with specified outside diameter greater than 60.3 mm but with a D/t of less than 75, the pipe end out-of-roundness tolerance shall not exceed 0.0075D or 5 mm, whichever is the less. This tolerance shall apply to the inside diameter. The pipe end out-of roundness tolerances for pipe of D/t >75 shall be agreed with the Principal.
Delete footnote "c" of Table 10 and replace with:
For pipe with D equal or greater than 219.1 mm, the diameter tolerance and out-of-roundness shall be determined using the measured inside diameter.
9.11.3.2 Delete this clause and replace with the following
The tolerances for wall thickness shall be as given in Table J4 (like offshore line pipes).
Table J.3
Modify as follows:
The pipe end out-of-roundness for pipe > 610 mm diameter and with D/t < 75 shall be
0.0075D with a maximum of 5 mm.
NOTE: Where required by the purchase order, tighter tolerances on pipe end out -of-roundness and internal diameter may apply to specific items.
Kind Regards
E-mail: p.banerjee.jpl@gmail.com
Description of the pipeline project is as follows:
Onshore Pipeline: API-5L- X65-PSL2, 56” Dia., 0.780” To 1.125” Wall Thicknesses.
Machines and welding procedure specifications should be capable to produce sound welds in 0 to 30% Slope of ground.
I will appreciate if you can help me with the following questions:
1- Which one is practical for production of a sound root bead? Internal welding machine (IWM) or internal clamp with copper shoes?Why?
Internal welding machine (IWM) has some advantages like higher speed of root welding, pipe lowering after root pass, better capability of welding in slope and better tolerance to Hi-low. But internal clamp with copper shoes is cheaper, easier to use and needs less maintenance. Thus I am eager to know if internal clamp with copper shoes is suitable for our onshore project or we must purchase an IWM?
2- According to API 5L standard maximum end out of roundness tolerance of normal pipes is 13 mm. While according to Annex J of API 5L standard, maximum end tolerance of out of roundness of offshore pipes is 10 mm. According to a specification (Prepared for Shell Canada Energy) maximum end out-of-roundness of offshore and onshore pipes should be 5 mm for automatic welding. In addition, tighter tolerances on pipe end out-of-roundness and internal diameter may apply to specific line pipes.
Which Criterion is acceptable and economical to purchase pipes (15, 10 or 5 mm)? Is tolerances less than 5 mm needed for welding root pass by copper backing ?
3- Some manufactures of internal line-up clamps (ILUC) offer strong clamps for automatic welding comparing to manual welding (like Serimax ILUC which needs112 bar pneumatic pressure supply & Hercules ILUC which applies 800 ton force).
Is there any calculation or experience for appropriate selection of “out of roundness tolerance and Internal Clamping force” to decrease Hi-Low to less than 1 mm?
4- Mechanical damage during shipping of pipes causes denting and ovalization. How damaged pipes can be repaired to acceptable tolerance of out of roundness? (Can mentioned high power internal line-up clamps (ILUC) reduce out of roundness for automatic welding?
5- Some manufacturers of pipe facing machines offer machines with high hydraulic pressure, for example Serimax Co. offers:
POWER SUPPLY REQUIREMENTS
Hydraulic Main: Flow: 225 to 340l/min
Pressure: 110 to 150 bar
Hydraulic Auxiliary: Flow: 15 to 24l/min
Pressure: 60/70bar – Maxi 110 bar.
Although some other machines with floating head cutters can produce reliable Narrow gaps which need less hydraulic pressure. Are floating head cutters necessary to produce sound welds? Which pressure range is appropriate for pipe facing machine?
Here are some paragraphs of mentioned line pipe specification (Prepared for Shell Canada Energy):
Modification of API 5L Standard:
Table 10 Modify as follows:
For all pipe with specified outside diameter greater than 60.3 mm but with a D/t of less than 75, the pipe end out-of-roundness tolerance shall not exceed 0.0075D or 5 mm, whichever is the less. This tolerance shall apply to the inside diameter. The pipe end out-of roundness tolerances for pipe of D/t >75 shall be agreed with the Principal.
Delete footnote "c" of Table 10 and replace with:
For pipe with D equal or greater than 219.1 mm, the diameter tolerance and out-of-roundness shall be determined using the measured inside diameter.
9.11.3.2 Delete this clause and replace with the following
The tolerances for wall thickness shall be as given in Table J4 (like offshore line pipes).
Table J.3
Modify as follows:
The pipe end out-of-roundness for pipe > 610 mm diameter and with D/t < 75 shall be
0.0075D with a maximum of 5 mm.
NOTE: Where required by the purchase order, tighter tolerances on pipe end out -of-roundness and internal diameter may apply to specific items.
Kind Regards
E-mail: p.banerjee.jpl@gmail.com
