MADEL O&G intend to be among worlds foremost commissioning services company having developed and introduced many of the specialist techniques which are now regularly used during the commissioning of process plant and pipelines.
BOLT TENSIONING AND TORQUING
With the varying problems that occur during hook-up and commissioning or shutdown operations, it has become apparent that an integrated service is required. MOG’s response has been to form a team capable of finding and repairing leaks. Offering this extra dimension can help save time and money since one contractor can control a complete leak testing project with fewer personnel onboard overall, but effectively doing more work.
Once leaks are identified MOG’s integrated service team will carry out leak repairs with the system depressurised. All flange bolts over 1” would be hydraulically bolt tensioned and all bolts below 1” would be hydraulically torqued or hand torqued. MOG will not carry out flogging under pressure.
The bolt load on the leaking flange is initially taken to the minimum acceptable level in accordance with specifications. The tension is then progressively increased in increments until the leak is sealed or until the maximum recommended bolt load is reached. If at this bolt load the leak has not sealed then this will be reported to the client to approve further bolt tensioning or allow inspection, gasket renewal or reworking.
The equipment will be supplied containerised with a tool coverage based on 50% of the number of studbolts on the flanges to be tensioned.
Procedures will be supplied including tensioning or torquing data sheets on specific classifications of joints and bolt material calculations. A flange record would be kept and issued for each joint repaired by this method.
Calibration certificates for equipment will be available and a completion package will be compiled upon successful assembly or repair of each joint.
MOG is the company that took the initiative of working with an alliance partner on leak testing
operations. We are the only company who has a track record and can demonstrate genuine cost and time
savings by the use of the integrated approach to topsides work. Our personnel are already cross-trained so again no time is lost.
MOG can offer any client improved productivity by offering an integrated package covering
hydrotesting, leak testing and bolt torquing/tensioning. The proportion of personnel dedicated to either
tensioning or testing can be adjusted to suit instantaneous priorities. This flexibility provides increased
efficiency and overall time and cost savings over the traditional method of two separate contractors for
testing and repairs.
This approach was encouraged for notable contracts in 1995 with significant direct service savings to the client, but moreover with a logistical benefit with reduced beds and flights which made the project viable.
MOG have used Hedley Purvis to date as the specialist contractor for bolt tensioning, and flange records are kept for all joints tensioned and non conformance/concession report would be issued for each joint.
MOG’s GENIUS leak testing computer can be adapted to include all the information listed on the manually produced flange records created by the bolt tensioning technicians. This would allow the flange number, leak number and flange record details to be referenced under one unique number. This would allow the operator the flexibility to call up a host of reports and historical data for information or post job analysis. The information/reports could contain a wide range of information, for example:-
– Flange description
– Size and class
– Gasket type, size and make
– No. of bolts, bolt diameter and length
– Condition of flange faces
– Grade of lubricant used/condition of bolts
– Type of joint (RF, RTJ)
– Tools used and serial numbers
– Maximum tension/torque permissible
– Recommended tension/torque
– Date of make up
– Name of operator and inspector/company representative
If this data was processed, analysis could be carried out to highlight which flange, flange type, gasket type etc. were causing problems during commissioning leak testing. This could lead to proactive management of maintenance techniques which would ensure subsequent operations are carried out more efficiently, therefore minimising operational costs and reducing shutdown time.
This proposed technique of total leak and bolt tensioning management will realise significant cost benefits over the total life of any facility.