Things that usually go wrong during commissioning

Chemical engineering, Plant designs related to chemical, petro-chemical or oil&gas, Operational assistance, etc.
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sharjeel
Posts: 33
Joined: 20 Apr 2010, 06:33
Area of interest: Chemical Engineering

Things that usually go wrong during commissioning

Post by sharjeel »

What are the things that usually go wrong while commissioning a turbine driven compressor? What are the things that we should keep in mind while going for the commissioning of rotating machinery? Can any body share a checklist or something for that?
Thanks in advance
Imran.Idris
Core Member
Posts: 59
Joined: 16 Mar 2010, 04:22
Area of interest: Chemical Engineering

Re: Things that usually go wrong during commissioning

Post by Imran.Idris »

You can face following type of general issues during commissioning phase of turbine driven compressor
1)Instruments out of calibration
2)Certain indications not appearing on the control penal / DCS
3)Suction and discharge filters & strainers may get choked during initial flow of steam / gas due to improper blowing.
4)Vibrations may go beyond limits due to improper fixing of equipment on its foundations.
5)improper behavior of control valves due to tuning issues
6)Leakages at flanges due to thermal expansions / due to improper tightenings / misaligned lines
7)Malfunction of securities that can cause nuisance tripping
8)Poor reaction of operator during emergency handling of the equipment due to lack of hands on training
9)Pay close attention to its lube oil and condensate recovery system
remember there is alway an inherent behavior of each new machine which can be very different from an already working machine of the same kind, so be prepared for it.
whaider
Posts: 54
Joined: 26 Apr 2010, 12:20
Area of interest: Chemical Engineering

Re: Things that usually go wrong during commissioning

Post by whaider »

Assuming the compressor has been factory tested, an important factor is integration of UCP with ICS. So do a thorough loop testing and software checks before you proceed. Even if software has been factory tested do a thorough site test before you proceed.
Waseem Haider
-thepetrostreet.com
qaisarabbas
Core Member
Posts: 134
Joined: 23 Mar 2010, 15:21
Area of interest: Metallurgy Engineering

Re: Things that usually go wrong during commissioning

Post by qaisarabbas »

very well summarized by imran.

10. Foreign materials / fabrication debris left inside process piping, this situation becomes very important when dealing with the suction lines of high RPM / business critical machines. Thorough flushing & boroscopy is highly recommended before initial start-up.
Q. Abbas
arcpro
Posts: 339
Joined: 16 Apr 2010, 18:46
Area of interest: Manufacturing Engineering

Re: Things that usually go wrong during commissioning

Post by arcpro »

Have you undergone all pre-commissioning checks?
Is complete check list available with you?
sharjeel
Posts: 33
Joined: 20 Apr 2010, 06:33
Area of interest: Chemical Engineering

Re: Things that usually go wrong during commissioning

Post by sharjeel »

This was the second thing I asked for in my query. Though we have a pre-com checklist available with us, however I wanted to compare it with some other industrial practices.
Thanks every body for your useful contributions.
arcpro
Posts: 339
Joined: 16 Apr 2010, 18:46
Area of interest: Manufacturing Engineering

Re: Things that usually go wrong during commissioning

Post by arcpro »

I am sharing some of the points for pre-commissioning of a Centrifugal Compressor:

1 RECEIPT INSPECTION FOR DAMAGES AND SHORTAGES.
2 STORAGE PROTECTION. ( INSPECT BEARINGS AND SEALS. RENEW FLUSHING OIL WHERE NECESSARY.)
3 BASE PLATE CHECKED FOR LEVELING.
4 BASE PLATE CHECKED FOR GROUTING.
5 COUPLING RUNOUT CHECKED ON ALL COUPLINGS.
6 COUPLING GAP CHECKED IN FOUR POSITIONS.
7 BLOWER AND DRIVER CHECKED FOR FREEDOM OF MOVEMENT.
8 SOFT FOOT CHECKED ON EACH HOLD DOWN BOLT.
9 COLD ALIGNMENT CHECKED AS PER REQUIRED.
10 JACKSCREWS REMOVED & FOUNDATION BOLTS TIGHTENED.
11 THE COLD ALIGNMENT RECHECKED.
12 SUCTION LINES CLEANED AND MAGNA-COATED AS REQUIRED.
13 PIPE SUPPORTS, SPECIFICALLY SPRING SUPPORTS, CHECKED TO BE WITHIN THE LOAD RANGE SPECIFIED ON THE PIPING DRAWINGS.
14 SPECIAL SPOOL PIECES INSTALLED. NO PIPING STRAIN ALLOWED.
15 CONE SUCTION STRAINER INSTALLED.
16 FLANGE BOLT HOLE OFFSETS AND FACE PARALLELISM CHECKED.
- VERTICAL BOLT HOLE OFFSET :
- HORIZONTAL BOLT HOLE OFFSET :
- ROTATIONAL OFFSET :
- FLANGE FACE PARALLELISM :
- FLANGE FACE SEPARATION :

17 LUBE AND SEAL OIL SYSTEM FLUSHED. RESERVOIR REFILLED WITH NEW OIL
AND FILTERS CHANGED. OIL TYPE_________.
18 RESERVOIR OIL HEATER CHECKED.
19 COOLING WATER SYSTEM CHECKED.
20 ALL PROCESS PIPING CONNECTED TO THE MACHINE AT THE SAME TIME.
( IT IS NOT ACCEPTABLE TO CONNECT ONE PIPE ONE DAY, ANOTHER
THE NEXT DAY, ETC.)
21 THE MAX MOVEMENT AT THE COUPLING DURING PIPING INSTALLATION IS 0.002".
22 GROUNDING STRAPS INSTALLED.
23 DRIVER DIRECTION OF ROTATION CHECKED.
24 ROTOR FLOATS CHECKED TO BE WITHIN THE MANUFACTURERS TOLERANCES.
25 COUPLING LUBRICATION AS REQUIRED.
26 COUPLING HUB FIT ON THE SHAFTS CHECKED FOR DISTANCE PUSHED ONTO THE
SHAFT/ INTERFERENCE AND SQUARENESS TO THE SHAFT. ( FACE RUNOUT )
27 THE KEYS AND THE KEY WAYS CHECKED FOR THE CORRECT FIT.
28 MECHANICAL & ELECTRICAL RUNOUT CHECKED AT THE VIBRATION
PROBE AREAS INCLUDING THE THRUST PROBES IF FITTED.
29 COUPLING GUARD INSTALLED.
30 COMPRESSOR AND DRIVER DOWELED.

Hope this would help you.
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