Customer Solutions《Contribution》

Effectiveness of Flange Tightening Training
and Expectations for VALQUA H&S at thePetrochemical Plant in Linyuan, Taiwan
1. Introduction
Since our founding, we have worked hard to stabilize

2. Flange Tightening andRemoval related accident

the national energy supply for 74 years. As the number

In recent years, the causes of accidents that occurred

one annual sales in the Taiwan petrochemical industry,during the disassembly of flange joints in thethe public is paying close attention to our occupational

petrochemical industry in Taiwan are as follows.

safety and environmental protection. The business

1．The target of the operation is not clear.

environment faces severe challenges due to the aging

2．Wrong gasket or material.

employees and the personnel shortage. We are

3．‌Flange disassembly residues are not properly

operational performance, and proposing humanresources technical training as a root countermeasure.
To improve operational performance, we haveintroduced a process safety management （PSM）
system, smart industrial security, and promoting
following four systems in industrial safety management
practice.

disposed.
4．‌No hazard analysis / notification for flange
disassembly operations.
5．‌No protective equipment when removing theflange.
6．There is no operational standard for flange removal
and tightening.

No.40

7．Lack of or no training for flange disassembly.

1．‌Build a complete process safety information system.

8．‌Old-fashioned tools are used to remove the flange.

2．‌The work permit shall be combined with the

9．Others.

investigation record of the pre-work tripartite
joint investigation and the graded supervisor.

If an accident occurs due to the above factors cause

3．Create an employee’s job performance passport.

death, injury, shutdown orders, fires due to leaks,

4．‌Investigate the root cause of accidents or equipment

unplanned shutdowns, or environmental protests will

failures.

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proactively grasping this situation, improving

severely damage the company’s management andreputation. Furthermore, employee fatalities andStrengthen basic training in core technology andinjuries can cause families to be displaced, especiallypersonnel（including contractors）. Flange tightening

affecting contractors, a vulnerable segment of society.

training is one of the primary tasks to reduce security

Flange removal work in the petrochemical industry

accidents and equipment leakages.

involves many people and a wide range of operations,from tightening and removing an individual flange totightening and removing piping and heat exchangers,
maintenance of rotary machinery, and cleaning
instrumentation and storage tanks. Therefore, an urgent
need is to implement effective management and provide
8Effectiveness of Flange Tightening Training and Expectations for VALQUA H&S at the Petrochemical Plant in Linyuan, Taiwan

flange tightening and removal training.

understand the effectiveness of standard procedures andthe reasons for implementing them so that they are

3. Overview of our training implementation

convinced to follow the standard tightening procedures.

To ensure the safety of the disassembly and assembly

and utilize it as a reference book for our repair

work of oil refining and chemical plant contractors, ourdepartment. In addition, as of September 2020, a total ofcompany established the "CPC Corporation Contractor

34 training sessions have been conducted for a total of

Equipment Tightening and Removal Training System

848 people. In July 2020, we received an endorsement

Implementation Guidelines"（C5731SHM10）in 2019. In

and public commendation from the Kaohsiung City

addition, the training content of flange tightening was

Government’s Labor Bureau, and were asked to promotecreated by referring to JIS B 2251 Flange Joint

this activity downstream to petrochemical plants in theTightening Method, a Japanese industrial standard

petrochemical industry. The first step has already taken

introduced by VALQUA, and through VALQUA’s training,

place on September 25, 2020, and we will continue tothe relevant knowledge and skills of the trainees incooperate with the Kaohsiung City Labor Bureau toremoving and installing bolts have improved.

implement this training.

We purchase HANDBOOK from Valqua and distribute

This training includes the following:
１．‌Selection of bolt and gasket specifications（e.g.,materials, dimensions, and tightening force）and

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others（e.g., anti-sticking / anti-seizing agents）.
２．‌Use of bolts and torque wrenches and torque3-1）Training equipment and planning,
Equipment location
The plan and location for conducting the simple practicaltraining are as follows:

calculation.
３．‌Understand the difference between cold bolting andhot bolting through the Valqua technical book
HANDBOOK（50% of the bolt tightening force isconsumed at the contact surface between the nut

No.40

and flange, and 40% is consumed at the nut andbolt thread. , The remaining 10% is effective axial
force, etc.）.
One particular point that can mention is that with the
VALQUA flange tightening training device, theparticipants can check whether the bolts are properly
tightened based on strain gauges and computer
calculations. In addition, verifying the presence ofdiagonal and circular tightening is possible, enabling the

Figure1

Practical test venue

participants to grasp the points they have not understoodso far and understand the standard tightening concept.
At our company, to acquire good tightening techniquesof bolt tightening and removal, we have introduced
Valqua’s flange tightening training equipment. We also
train our employees and contractors to use these devices
to verify the skills of the installers and to help them
9

Figure2

Practical test pipe jointCustomer Solutions《Contribution》

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Material room design plan

No.40

3-1-1）T‌ he location of the tightening and removal

unit, foam leak detection unit,

flanges are as follows.

3/ 4 B Yatoi tube, 3 sets each oflarge and small F wrenches,

1．‌Area：Approximately 5m×10m（Figure1）.
※ The room is fully air-conditioned.

hanging sign, steel ruler, steel2．‌3 sets of 150lb×6B flange joint（Figure2）.

brush, tool basket, bolt storage

3．‌Material room ①：‌3 sets of 30L air cylinders,pan, etc.

3 spare cylinders

9．‌Others：‌6 helmets, gloves, fire extinguisher, safetyT he air header is attached tomarkers installation, first aid kit, lockers,

these air cylinders（Figure3）.

etc.

4．‌Material room ②：‌3 sets of air compressor, airheader and hose.
5．‌6 air breathing masks and 3 sets of hoses.
6．‌Tool set：12 of 3/4B ratchet wrenches.

3-1-2）‌Flange tightening experience area andflange tightening hands-on installation

VALQUA is the main planner（Figure8）.

7．‌Accessories：‌6B×150lb×1/8B 3 thin blind flanges,
consumables 6B×150lb non-asbestos

3-2）Training Courses

gasket and spiral gasket consumables.

As a reference in all fields, we introduce our training

8．Other accessories：‌scraper, cleaning and lubrication

courses. The one-day training course is divided into10

Effectiveness of Flange Tightening Training and Expectations for VALQUA H&S at the Petrochemical Plant in Linyuan, Taiwan

Ⅲ．‌Check for pressure test leaks above 3kgf / cm²
and（clean）organize the location.

4. Training effect
The flange tightening and removal training are similar
to the implementation of factory work, but both focus on
Figure4 rder of flangeOtightening

Figure5 Order of bolt removal

pre-work precautions. Next, each member will sign andgain the approval（work will start after confirmation of

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classroom lectures and practical exams. The content of

the construction site, construction details, environmental

the classroom lectures includes explanation of relevant

treatment of the construction surroundings, audit of theaccident cases, hazard recognition of the working

treatment status with blind flanges drawings of theenvironment, use of respiratory protection equipment,

construction piping or equipment, hazard precautions,safety of flange tightening and removal, general

construction methods, etc., and the issuance of aknowledge（gasket selection, piping material andconstruction permit on the same day）
. The contractor’s

specification, bolts, tools, etc.）, and introduction of

pre-work hazard notification and safeguard preparation

process flow chart（P&ID）for employees. JIS B 2251

are more important than the actual work; a lack ofintroduced by Valqua is adopted for the flange

environmental awareness can lead to the threat of death

attachment / detachment training. The flange tightening

as soon as disassembling the flange. For example, anprocedure is to temporarily tighten diagonally（Figure4）

accident may occur during hydrogen sulfide and otherwith four levels of tightening force of 10%, 20%, 60%,
and 100%, and then tighten four times with 100%tightening force（clockwise, Or counterclockwisetightening）. The order of bolt removal is followed by our

No.40

specifications, starting at the bottom of the flange andworking from the bottom up（Figure5）. The "pause
inspection point" is placed at the bottom from where
three bolts are removed to protect the operator.
■ Practical test program：
Ⅰ．Before starting work, check the following.
1．Check the target work（installation of white
construction sign）.
2．Check the measurement value of pipe residues（select protective equipment）.
3．‌Check the processing status of the pipe contents（rechecking safety before installation）.
4．Check the target dimensions, specifications,materials, etc.
Ⅱ．‌While working wear respiratory protection / check
discharge / remove flange / install blinds（yellow
construction signs）/check discharge / remove
closure plate / conduct restoration.
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Figure6 Three-party joint questionnaire form before construction

Customer Solutions《Contribution》

toxicological work. However, steps such as three-party

These regulations and measures are significant for thejoint investigation and pre-work training before thepetrochemical refining industry. We aspire to become an

actual work are generally not emphasized. In addition,industry leader in industrial safety. We have alreadybecause they are considered unprofitable man-hours andtaken a big step, but in the future, we are working to

do not recognize the danger they pose to the workers,

enable mutual recognition, learning, and dissemination of

the flange tightening and removal training involves

training within the industry.

much effort and the necessary steps to master the

Linyuan Petrochemical Plant revised the labor

practical skills. In some cases, they become unsuccessful.

procurement SOP from the root and applied it to new

Until now, there has been no standardized training

procurement projects from July 1, 2019, and actively

course for flange tightening and removal, and veteranpromoted and participated in processing old projects

employees with long service years have guided workers

with additional methods. Within six months, thebased on their experience. The work procedures are alsoestablishment of "equipment flange tightening anddescribed in our "Piping Construction Standards（aremoval training" was planned and completed, and also

document of the Ministry of Transportation of Taiwan,

the number of successful candidates for contractor

equivalent to the Ministry of Land, Infrastructure,

dispatch training by September 2020 reached 331

Transport and Tourism of Japan）"（CS-102-0006-5）SOP（Figure7）.

and the related contract work agreements. However, inAt the Lin Yuan Petrochemical Plant, training began

the case of flange tightening, for example, it was difficult

as follows:

many times to tighten temporarily or how many times
to tighten fully, and standard work procedures were● May 7, 2020
Conducted training for new employees.
● May 21, 2020 and June 5, 2020

lacking especially in the case of flange removal. For‌Conducted training for engineers and next

example, the order of removing bolts is from bottom to

executive candidates（Figure8）.

top, from a distant place to the neighborhood, and● August 20, 2020 and September 4, 2020

whether to disassemble diagonally, etc. We solved the‌In the other divisions, "equipment flange

problem with the newly established“CPC Corporation

attachment / detachment and tightening /Contractor Equipment Tightening and Removal

fixing" tour training was conducted in two

Training System Implementation Guidelines”

stages, with a total of 46 participants.

（C5731SHM10）. For tightening, we adopted the strongly● August 2020

supporting JIS B 2251 standard and purchased a‌No.3 Aromatics Unit Group（name of a CPC

VALQUA flange tightening training equipment. By

Corporation work group）/ A total of 50 people

doing so, we can compare the previous tightening

participated in the re-measuring training formethod with the new method, JIS B 2251 standard, in

HEPCO repair contractors of flange tightening

real-time from the radar image on the screen, allowing

and removal operators.

reliable and effective verification. On the other hand,when disassembling the flanges, a group discussion

The actual effect of the project appeared as a great

method was adopted by experts to specify the order ofbenefit during the shutdown maintenance of No.4

detachment. In the case of vertical flanges, three bolts

Naphtha Cracker group（name of a CPC Corporation

should be removed from the bottom to the top and thenwork group）at the end of 2019 and the New No.3

stopped for inspection. Work should continue after safety

Naphtha Cracker group（name of a CPC Corporationis confirmed, and in the case of horizontal flanges, thework group）at the beginning of 2020. The quality oforder of removal was determined to be from the bolt

the contractor’s equipment, the flange tightening andfarthest away from the person.

removal was greatly improved. In addition to reducing
12

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to determine what was correct on-site, such as how

No.40

Effectiveness of Flange Tightening Training and Expectations for VALQUA H&S at the Petrochemical Plant in Linyuan, Taiwan

5. Conclusion
We would like to thank VALQUA for their cooperationin providing flange tightening and removal standards
and training. We hope that more workers andcontractors will receive the training to maximize theirbolt removal and tightening skills and enhancetightening safety. We would like to maximize the bolt
removal and tightening technology and improve thesafety of tightening by training more workers andFigure7

Contractor flange tightening and removal training.

contractors.
In response to the government’s urgent demand forindustrial safety measures throughout the petrochemicalindustry, we will actively introduce leading-edge
technical systems and equipment to fulfill our
responsibility. We will then spread the use of these toprovide substitute training to industry personnel toensure that the petrochemical industry can be managed

Winter 2021

sustainably as a safe industry.

6. References
1）‌CPC Corporation Contractor Safety and HealthManagement Act（2020 / 10 / 20

5731-SHM-01）

2）‌Taiwan National Oil Corporation Piping Installation

No.40

Standard（2018 / 04 / 12 CS-102-0006-5）
Figure8

Flange tightening training

3）‌Ring joint gasket flange installation for Taiwan
Chinese-Oil Corp. Standard

industrial safety incidents, flange tightening training
can reduce the uncertainty of downtime due to leaks（2018 / 02 / 23 CS-102-0003-1）

and reduce the rate of flange leakage of volatile organic

4）‌Taiwan PetroChina Contractor Equipment Removal
Training Program Implementation Guidelines

compounds （VOCs）. Since the training has been
conducted for a short period, it is impossible to quantify（2020 / 07 / 10 5731-SHM-10）

the training effect on reducing flange leakage rate at5）‌VALQUA STC Training Materials

this stage. But we are confident that it will be effective（2019 / 03 / 29Document No. 12015-001）

and hope to be able to prove it with quantitative datain the future.

Kinsei Hayashi
Manager of Industrial Safety Section,
Lin Yuan Petrochemical Plant,
Petrochemical Division,
Taiwan National Petroleum Corporation
13