SIPCHEM K8 HYPER COMPRESSOR OPERATIONAL EXPERIENCE

Anas Softa - SIPCHEMAlexandru Roman – Burckhardt Compression

Specification Value

Compressor type K8Serial no. 200163Weight of compressor 225,000kgYear of manufacture 2012Process gas Ethylene (C2H4)Mass flow 87,360 kg/hStandard volume 70,350 Nm3/hSuction Volume 200 m3/hSuction pressure 286 baraDischarge pressure 3,101 baraMaximum power requirement 15,570 kWElectric motor rating 18,500 kW

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Cylinder/Valve Lifetime Analysis

Hyper Central Valve Replacement (as of 15th May 2018)

Cylinders

Running Hours 1st

Valve

1st

Replacement Date

Running Hours 2nd

Valve

2nd

Replacement Date

Running Hours 3rd

Valve

3rd

Replacement Date

Running Hours 4th

Valve

1A 12,434 7th May 16 13,042 28th Dec 17 948 11th Jan 18 2,720

1B 13,395 19th Jun 16 13,928 - - - -

1C 12,624 16th May 16 14,703 11th Jan 18 887 - -

1D 9,115 6th Dec 15 16,066 4th Dec 17 3,575 - -

2A 2,008 7th Jan 15 11,387 19th Jun 16 13,928 - -

2B 12,362 3rd May 16 14,959 - - - -

2C 19,152 20th Feb 17 8,118 - - - -

2D 19,152 20th Feb 17 8,118 - - - -

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Cylinder/Valve Lifetime Analysis

Hyper HP-Packing Replacement (as of 15th May 2018)

Cylinders Running Hours 1st Replacement Date Running Hours 2nd Replacement Date

1A 25,903 11th Jan 18 2,720 -

1B 29,052 - - -

1C 29,052 - - -

1D 25,049 4th Dec 17 3,575 -

2A 29,052 - - -

2B 29,052 - - -

2C 29,052 - - -

2D 19,156 20th Feb 17 9,980 -

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Cylinder/Valve Lifetime Analysis

• Cylinder lubrication rates

• Overall 1st stage lubrication is 140% over recommended rate

CYLLUBRICATION

POINT

TIME(SECONDS)

ACTUAL FLOW RATE(LITERS/HOUR)

Actual Vs Recommended (C2H4+VA) TOTAL 1ST

STAGE(L/HR)

1C 2 41.45 1.30 226%

12.89

1C 1 46.87 1.15 188%

1C 3 45.5 1.19 124%

1A 2 66.18 0.82 104%

1A 1 71.11 0.76 90%

1A 3 65.86 0.82 55%

1B 1 53.23 1.01 154%

1B 3 58.7 0.92 74%

1B 2 57.05 0.95 137%

1D 1 45.31 1.19 198%

1D 3 36.12 1.50 182%

1D 2 41.95 1.29 222%

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Cylinder/Valve Lifetime Analysis

• Cylinder lubrication rates

• Overall 2nd stage lubrication is 20% lower than the recommended rate

CYLLUBRICATION

POINTTIME(SECOND

S)ACTUAL FLOW

RATE(LITERS/HOUR)TOTAL 2ND STAGE(L/HR)

2C 2 193.09 0.28 -63%

7.85

2C 1 236.23 0.23 -70%

2C 3A 84.03 0.64 29%

2C 3B 166.24 0.32 -35%

2A 2 75.77 0.71 -6%

2A 1 101.57 0.53 -30%

2A 3A 305.59 0.18 -65%

2A 3B 134.07 0.40 -19%

2B 1 64.67 0.84 10%

2B 3A 130.29 0.41 -17%

2B 3B 117.87 0.46 -8%

2B 2 83.71 0.65 -15%

2D 1 57.42 0.94 24%

2D 3A 194.1 0.28 -44%

2D 3B 83.88 0.64 29%

2D 2 162.14 0.33 -56%

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Hyper Condition

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Hyper Condition

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Hyper Condition

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Cylinder/Valve Lifetime Analysis

• 2D HP-Packing after 19,156hrs. Replaced Feb. 2017

• High leak gas flow reaching 1000kgs/hr

• 1st Packing replaced.

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Cylinder/Valve Lifetime Analysis

• 1D HP-Packing after 25,049hrs Replaced in 4th Dec 2017• 1st HP-Packing Replacement• Cylinder shrunk liner cracked along it’s complete length• Fracture origin is located in a threaded hole in the crank side face of the

shrunk liner.• Other possible sources for a fracture found to be corrosion pits below the last

thread.

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Cylinder/Valve Lifetime Analysis

• 1A HP-Packing after 25,903hrs Replaced in 11th Jan 2018• 1st HP-Packing Replacement• Leak gas increased to 500+kgs/hr. Bubbles appeared in cooling oil return sight

glass• Packing cup number 5 radially cracked with 4 x 4 x 0.6 mm Inconel particle

embedded on the inner cylindrical surface• Inconel particle source from pressure breaker retainer ring where it was found

missing a small piece

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Cylinder/Valve Lifetime Analysis

• Gas bubbles in cooling oil return noticed @ 28th Dec.• Inter-stage pressure reduced & suction temperature increased to lower

compressive load on the HP-Packing.• 1A discharge temperature increased +20 degrees after few hours.

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Cylinder/Valve Lifetime Analysis

• 1A Central Valve after 13,042hrs Replaced in 28th Dec 2017• 2nd C.V Replacement for 1A• Temperature increased up to 950C• Suction Valve Body cracked radially across the five pass-through bores and

outer circumference• Visible fretting in the central area on the cylinder head side of the valve body

and around the circumference.

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Cylinder/Valve Lifetime Analysis

• Material strength is not adequate for the stresses at the suction valve body.• Fatigue degree of utilization at the radii of the contact surfaces is over 227%, which

means the safety factors are not fulfilled.

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Cylinder/Valve Lifetime Analysis

• Solution is to cut away the support surface in the center to uncouple the two parts.• Fatigue degree of utilization at the radii of the contact surface is over 86%.• Modifications are planned accordingly to machine 1mm of the central sealing

surface hub.

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Broken Tie-Rod

• Cylinder 2B tie-rod broken in February 2017• In-house tool fabricated for its removal• Crack location at threaded area• Failed due to high cycle, low-load fatigue and corrosion pits forming notches.

QUESTIONS?