RCA Nam e Shutdow n of plastics production line Report Num ber 1.3
Report Date 3/15/2014RCA Ow ner Edw ard Fitch
Root Cau Analysis Report
Problem Statement
Focal Point Shutdow n of plastics production line
When
Start Date 3/8/2014End Date 3/11/2014Start Tim e 0800End Tim e 1530
马关条约Unique Tim ing Shutdow n occurred during norm al production run, 24-hour production schedule,Where Plastics Business Houston, TX Pellet Conveying
Blow ers B-100 and B-200
Actual I mpact
Cost 20 lbs/day polystyrene vented to atm osphere
$0.00Lost annual profit乡村文化墙
$60,000.00Annual repair costs
$30,000.00Actual I mpact Total:$90,000.00
Frequency 6 tim es Frequency Notes 6th unplanned shutdow n of the production line in last 12 m onths Additonal lost profit of extended dow ntim e
$60,000.00
Custom er lost confidence in ability to provide m aterial
$0.00
Incread exposure to injury for rvice frequency of
o utages
$0.00Potential I mpact Total:
$60,000.00
Site Location System Com ponent
Environm ental Revenue Cost per year
Potential I mpact
Revenue Custom er Service Safety
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Report and chart generated by Sologic’s Caulink software.
Page 2 \ 9 Report Summaries
Executive Summary
Between 08-March-2014 and 11-March-2014, the plastics production line had to be shut down becau
of issues in the vacuum transfer system. The main blower stopped working when water, which had
accumulated in the blower, tripped the circuit breaker. There is a backup blower system, however it
would not start becau the backup blowers were ized.
Water in Primary Blower:
The conveyance system is a clod loop. The air in the system picked up water vapor from the 150 F
water bath. The system was not designed with a knockout pot becau at the time, Engineering did
not foree the need for one. Normally, excess water vapor is removed by the air dryer. However, it
was not working properly becau its condenr was plugged. Solids accumulate in the condenr and
they were not being cleaned out. There is no PM scheduled for cleaning the condenr. Solids take
the form of both accumulated polymer and pellets. The polymer is the result of residual monomer that
is not being stripped out of the process. There is no monomer stripper becau Engineering did not
foree the need. The pellets accumulate when the bag filters fail. Bag failures are caud by the fact
that the bag material tore and is wrong (thin felt bags) for the current application. The tears were
generated from sharp bag cage edges, and the differential pressure was causing the tears to grow
larger, which was allowing small pellets to enter the system. The cage edges were sharp due to metal
burrs not cleaned after a recent maintenance repair. The types of repairs are not common and are
typically not performed as entire OEM cages are usually replaced in lieu of repairs. The repairs were
necessary becau the production line stoppage was causing extreme revenue loss and there were no
immediate OEM cage replacements available.
Backup Blower Unavailable:
The backup blowers were ized becau the lobes and housing had rusted. The blowers are made
from steel and they are expod to the same wet circulating air as the primary blower system -- both
are tied in to the main line. There are no isolation valves that would parate the blowers -- the need
was not anticipated during the original design.
Solutions intended to prevent recurrence of the shutdown due to blowers tripping or rusting include:
- Adding quarterly condenr cleaning to CMMS PM system
- Installing a liquid level switch in front of the blowers
- Changing bagging material for pellets to Gor-tex so filler filters are not failing
- Updating engineering standards and specs to include RCA learning to better spec PM plans
丹田发声训练- Performing design reveiw of existing system to assure compatability with current operating
conditions and redesign as needed
Cau and Effect Summary
The six shutdowns of the plastics production line over the last year have been caud by the loss of
vacuum to operate the transfer system. The loss of vacuum is caud by the main blower tripping out
on high amps and the back-up spare blowers not starting. The main blowers are tripping becau they
are filling with water, and the spares won't start becau they ize due to rust. The main blowers are
filling with water due to the water vapor prent in the conveying air, becau there is no knockout pot
and it is a clod loop conveying system. The spare blowers are rusting becau they are steel, they
are expod to air, and they also are filling with water. The discharge piping of the blowers tie together
and there are no isolation valves. The water vapor is prent becau the pellets are being pulled into
the airvey line after the water bath, the bath operates at 150 degrees F and the air dryer is not
working. The dryer doesn't work becau the condenr plugs frequently fill with solids becau either
polymer or pellets accumulate. The condenr is never cleaned becau there was never a PM put in
place to clean it. The pellets accumulated due to torn felt bag filters that allowed small pellets to enter
the system.The torn bags were caud from sharp cage edges left from prior maintenance repairs. The
maintenance team was unaware of the need to debur the edges after repair. The uncommon cage
适合孕妇的运动repairs were required becau OEM replacement cages were not available. The polymer accumulates
Page 3 \ 9 becau the residual monomer prent polymerizes. The monomer is prent becau of the
unreacted monomer in the pellets is not stripped out becau there is no stripping system. The lack of
a stripper, lack of a knockout pot, and lack of a PM to clean the condenr were caud by the
engineering team not anticipating the need for the things.
Label Solution Cau Note防紫外线伞
Assigned
Criteria Due Status Term
Cost
Solution Cau Note Assigned
Criteria Due Status Term
Cost
Solution Cau Note Assigned
Criteria Due Status Term
Cost
Solution Cau Note Assigned
Criteria Due Status Term
Cost
Solution Solutions
ID
Description
1
Update engineering standards and specs to reflect the RCA learnings Engineering didn't anticipate need
Opportunity to included best practices and better spec preventive maintenance plans.Solution does not prevent recurrence of focal point, but is a value-added solution that will help enhance the preventive maintenance program.Jason Dufner Fail 3/23/2014Selected Long
梦见一条蛇
$1,000.00
2Change bag material to Gore-tex Thin felt bags being ud
Existing material in not sufficient. Gore-tex has been evaluated and is the best viable substitute.Hale Irwin Pass 3/27/2014Approved Long
$2,000.00
办公室老板3Install vacuum jets to strip and recover monomer.No monomer stripper in system
Solution is intended to aid in keeping condenr from plugging.Hale Irwin Pass 4/13/2014Identified Long
$5,000.00
4Add quarterly condenr inspection/cleaning to CMMS PM system.No PM for cleaning condenr
Criticality of condenr maintenance was unknown prior to this analysis.Ryan Moore Pass 3/16/2014Approved Medium
$0.00
5Install liquid level switch at low spot in piping in front blowers.
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Cau Note Assigned
Criteria Due Status Term
Cost
Solution Cau Note Assigned
Criteria Due Status Term
Cost
Water accumulated in blower
Solution will aid in understanding if liquid is ttling in or near blowers.Hale Irwin Pass 4/13/2014Approved Long
$2,500.00
6Perform design review of existing system to assure compatability with current operating conditions and redesign as needed.
Equipment not updated for new operating conditions辛字组词
Jason Dufner Pass 3/16/2014Identified Long
$1,000.00
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