Comprehensive Failure and Repair Report of Plansifter

This document presents a comprehensive technical report on the failure and full restoration process of Plansifter 105 (Model MPAH-825).
It details every stage from the initial breakdown through failure analysis, root cause identification, and execution of corrective and preventive actions.
The report also includes structural welding procedures, component fabrication, reassembly, testing, and performance verification.
Supported by photographs, timelines, and operational data, it demonstrates the successful recovery of the milling system with zero injuries, 100% reliability, and optimized downtime management — a practical case of engineering excellence in industrial maintenance.

1. Equipment: Plansifter MPAH-825, Serial Number 10004359
Date of failure: August, 42022
Time: 09:00 pm
As well known, this kind of work takes a long time to execute and repair damaged
parts, and to keep Jeddah plant aligned with planned programs, the operating
team decided to empty the sifter boxes and bypass the milling process at this
stage and transfer the products directly to the 4BKCroller mill and reduce mill
capacity to the following limits (300-350tons) for continued operation.
Fig.1
Fig.2
Meanwhile, the maintenance team can prepare the necessary materials and
obtain approval from the COO, to dismantle the plansifter and resume work.
This solution was proposed by Saad Al-Jadaani, production manager in charge.
Problem statement: Mill B was temporarily out of service due to a sudden failure of the Plansifter 105
Equipment Failure Report

2. After obtaining the approval and completing arrangements, the first step of the corrective
action has been initiated.
The maintenance team started to dismantle the plansifter components
(Fig.3), along with the investigation
and visually inspect the general condition of all components, to analyze the root causes of the failure and
identify side impacts in each part separately, then to find suitable technical solutions to rebuild the sifter
with high reliability, reassemble it and operate it efficiently.
Date
: August, 112022
Start Time: 08:30 am Implementation of the corrective action
Fig.3
During the implementation of this procedure, the bypass pipes will be installed after dismantling and
removal the parts, then restarting B mill again.
Plansifter 105 Report Stage
1

3. The plansifter was dismantled and moved the affected parts to a nearby location, after
which the bypass pipes were installed
(Fig.4), and the mill restarted.
Fig.4
Date
: August, 112022
Finish Time: 08:30 pm Work carried out
Plansifter 105 Report Stage1

4. Fig.5 Fig.6 Fig.7
The plansifter cross-member was fractured (Fig.5), where repeated stress changes caused the initiation
and growth of fatigue micro cracks under the surface in the weakest place (welding joints) at bolts
connection side
(Fig.6), where this crack expanded and led to a sudden fracture of the cross-member
(Fig.7) without prior indications. This usually happens after a long period of repeated stress.
Note: There was no damage to the fiberglass suspension rods.
Failure description
Date
: August, 112022
Plansifter 105 Report Stage1

5. Serious damage occurred at several critical locations in two of the
three parts of the plansifter, as described below.
The cross-members
The steel frame connection
positions for the right sieve box
The steel frame connection positions
for the central drive section
Fig.8
Fig.9
Fig.10
Date : August, 112022
Plansifter 105 Report Stage1
The side impacts of the failure

6. •We will take the central columns of the old Plansifter and use it as spare parts for damaged ones (Fig.11) .
•The upper and lower bearings will be changed.
•All work will be carried out according to the operating manual
•Workplace safety and health will be adhered to during repairs.
•Preparations of replacements is in progress and a notification will be made shortly.
Fig.11
Summary-Stage 1Date : August, 112022
Best regards
Ayman

7. Off-site procedures
The preparations for the repair began with the transfer the old Plansifter from the yard to the central workshop.
The central columns of the old Plansifter were carefully removed, cleaned and prepared for assembly.
The steel thickness of the cross-members beam was confirmed, then the beam was fabricated, formed according to
the required shape.
Plansifter 105 Report Stage2
Date : August, 182022

8. The mounting brackets have been balanced and properly installed to ensure that they are identical to the three parts
of the plansifter during assembly.
The beam finishing work is in progress.
Plansifter 105 Report Stage2
Off-site procedures
Date : August, 182022

9. In-site procedures
The damaged columns of Plansifter 105 were removed, and the surfaces were cleaned and prepared for assembly.
The replacement columns are identical to the drive section and no modifications were necessary.
Affected welding joints have been repaired.
The columns were mounted with accuracy.
Plansifter 105 Report Stage2
Date : August, 182022

10. Each column side was gradually welded at regular intervals to maintain the structure and avoid thermal stresses.
The steel frame for the sieve box has been repaired.
The plywood boards were purchased to fabricate the bases of the sieve boxes, as well laminate sheets for the walls.
The threaded holes in the sieve boxes have been repaired.
In-site procedures
Plansifter 105 Report Stage2
Date : August, 182022

11. •The finishing and minor adjustments work of the welded parts in the final stages.
•The executed work will then generally be inspected and tested to ensure there are no technical defects.
•Then starts the carpentry work to install the laminated wall sheets and sieve boxes bases.
•The estimated time for repair work is approximately 3 days.
•Assembly and installation work scheduled to start by the end of this week.
Best regards
Ayman
Summary-Stage
2
Date : August, 182022

12. As announced in the summary of stage 2on August 18, 2022, that the assembly and installation work
will be to start by the end of the week.
Preparation for the last Battle
•To set a time frame and target date for completion.
•Define the main tasks and actions required for implementation.
•Develop a communication plan and train the team members on instruction.
Finally, it has been decided that the target date for the Battle
on
August, 25 2022
Estimated time for completion of work is 24hrs.
Therefore, an implementation plan meeting was held with the team supervisors
to determine the following:
Meanwhile, preparations were in their final stages: Finishing works -Lifting
handling equipment to site...etc

13. After obtaining approval, and in the morning of the implementation day, B mill was shut down as
scheduled and the team began to implement the following procedures:
Dismantled the bypass pipes and clear the installation sites from any obstacles.
The steel supports were fixed underneath the drive section and the sifter boxes.
Transferred the sieve parts successively and placed them on the supports.
Preparatory work was carried out for the suspension of the sifter and for the outlets in the floor.
Date
: August, 252022
Start Time: 08:00 am
Plansifter 105 Final StageReport
Implementation day

14. The team aligned the 3 sections on one plane on the steel supports, placed the sifter boxes next to the
drive section, and connected them with dowel screws.
Then they bolted the boxes together with the connection bolts, and tightened the bolts uniformly and
alternately to avoid distortions. The 2cross-members beams were Fastened with 8connection bolts.
All M20bolts tightened torque = 200 Nm.
Date : August, 252022
Plansifter 105 Final StageReport
Assembly of the plansifter

15. The team hoisted the plansifter by 4 eyebolts, on the drive section to the prescribed height, and accurately leveled
the sifter by means of a spirit level, and by using a spindle socket underneath each corner of the plansifter.
Then the fiberglass suspension rods were installed on the holders at the ceiling. The rods were fastened to the
cross-members with the clamping plates, and then tightened according to the instructions.
The clamping bolts tightened torque =
90 Nm.
A safety wire rope was mounted for each of the four rod groups.
Date : August, 252022
Plansifter 105 Final StageReport
Suspension and level of the plansifter

16. The last steps before starting up the machine, and carry out the trial run:
•Adjusted the centrifugal weight to distance A: 85 mm as per instructions.
•The transmission belts were installed on the pulley of the shaft.
•Compartment preparation: Inlets, Outlets, spout connections.
•The electrical installation has been carried out and checked.
•All threaded joints were tightened securely.
•The sifter doors have been reinstalled.
•The sieve stacks are correctly braced with inlet frames and door closures.
•All screws have been tightened sufficiently.
Date
: August, 262022
Finish Time: 01:50 am
To see the trial run, please click on
the link below:
PL-105 Trial run
Plansifter 105 Final StageReport
The last steps

17. •As promised previously, the plansifter 105 has been rebuilt with high reliability, reassembled and operated efficiently.
•For the first time and without experience in such failures, the plansifter was rebooted with 100% success, and 0% injury.
•After we obtained the metal test result from the damaged part, we were able to find the right material for the parts to
be manufactured locally by one of our trusted partners.
•We saved a lot of time and money that would have been spent abroad on manufacturing and procurement.
•The work was done in a shorter time than necessary.
•The COO's visit had a significant impact on the team's motivation.
•The plansifter operating under periodic monitoring.
•To see the Plansifter operating in full capacity, please click on the link :PL-105 in operation
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Summary-Final Stage
Date : August, 262022
Best regards
Ayman