Customer Solutions

Precautions when considering usage
and troubleshooting（FlectorTM）
1. Introduction
Expansion joints, a type of pipe joint, have been widelyused in various plants since the past. An expansion
joint is a component that absorbs the effects of mutual
displacement between structures, and is indispensablefor the safe operation of various plants. Therefore, it is
crucial to carefully select them, because installing andoperating an incorrectly designed product can lead to
There are metallic and non-metallic expansion joints.

Figure1

Summer 2021

equipment damage and possibly a major accident.
Photograph of external view of No.FLEXThe non-metallic expansion joint manufactured by ourcompany is called FlectorTM.
This report provides a brief product overview of FlectorTM,
precautions to be taken when considering its usage, as
well as usage troubles and their countermeasures.

No.41

2. Product overview
2-1）No.FLEX（Flex）
This product is a combination of metallic parts（flanges,etc.）and a non-metallic cover（Figure1）.The cover partis made of integrally molded rubber and reinforcing

Figure2

Photograph of section view of No.XP-221

Figure3

Photograph of external view of No.PRBT

fabric, therefore eliminating any joints and providing
excellent airtightness, long-term flexibility, andradiation resistance.
Major applications: Ventilation equipment in nuclear
power plants.
2-2）No.XP-221
This product is a combination of a cover and metallicparts（flanges, etc.）formed by sewing and bondingorganic and inorganic cloth, film, etc.（Figure2）. It is
used in a wide range of industries due to its high2Precautions when considering usage and troubleshooting（FlectorTM）

degree of freedom in design and high versatility.

have a significant impact on the performance andMajor applications: Exhaust gas, boiler and dust

longevity of the product and therefore caution iscollector lines in various plants, etc.

required. In this section, the reasons why this isnecessary will be explained in detail for each item.

2-3）No.PRBT（Rubber boots）
This product is made of the same cover material as3-1）Nominal dimensions（Mounting dimensions）

No.FLEX, and is installed by wrapping a fan-shaped

It is critical that the mounting dimensions are correct,

cover with fasteners sewn on both ends around theotherwise the product cannot be installed. Therepipe penetration area, closing the fasteners, sealing themight occur a problem of discrepancy between thearea with an amorphous sealing material, and thendrawings and the actual site due to lack of management

fixing both ends with metallic bands（Figure3）. Thisof revision and abolition. Therefore, it is important toproduct is specially designed to seal the gap between

confirm the current status.

the pipe at the pipe penetration area and to absorb
pipe displacement.

3-2）Installation location and fluids

Major applications: Pipe penetrations in walls and floors

If installed outdoors, it is necessary to implementof power plants.

appropriate measures because the surrounding
environment is harsher than indoors, including rain,

Summer 2021

3. P
 recautions when considering
usage

ultraviolet rays, and temperature differences. As for fluids,

Figure4 shows a product specification sheet. The items

inner cylinder will be necessary, and this is important

colored in pink are the minimum necessary information.

because it has a significant impact on longevity.

the presence or absence of corrosiveness and dust willlead to determining whether a cover configuration or

If there is insufficient or incorrect information, it will3-3）D esign conditions, flow velocity, flow rate,

No.41

and distance between mounting surfaces

Valqua Flector Specifications
Date

Temperature and pressure are important criteria for

Sales Office
Name of Contact Person

Dealers
Customer Name

Quantity

Sales channels

Yes - No /Date of previous use
Usage Examples（Required for export）(Previously use o/#)Inclusion of venues

Nominal sizeamount of displacement and the space between the

Purpose of use
Name of facility or equipment
Installation point

Installation Location

Indoor / Outdoor

Dust: Yes (amount) ・ No

(Ingredients)
Temperature(°C)
Pressure(kPa)Corrosiveness: Yes ・ No
In operation

Temperature(°C)
Pressure(kPa)

Axis direction(X)
Axis vertical
Displacement(Y)
Axis level(Z)

Flow rate
Flow direction

Materials

Horizontal/vertical (top to bottom, bottom to top) OtherFlange (non-contact gas part)

Inner tube (gas contacting part)

Bolts for mounting

GasketRestricted materials

OtherMiddle coat
Top Coat
Finish colorOther matters

3The cross-section of the design may change dependingon the flow direction and mounting position. Since theflow direction will also be printed on the product, it isnecessary to provide this information.

Undercoat

Figure4

combination.
3-4）Flow direction and mounting position

Mounting length

Pretreatment

Coating

mounting surfaces, there is a possibility that one or theother cannot be addressed depending on theFluid name

Design conditions

checking both design parameters and operatingconditions. Since there exists a correlation between theIf there are specific dimensions, please indicate them separately on the drawing.

Terms ofUse

cover selection. Optimum design can be achieved by

Product specification sheet

Customer Solutions

4. E xamples of troubles andtheir countermeasures

XP-221 with the inner cylinder during shutdown. Since
it was installed perpendicular to the ground, powder
accumulated between the cover and the inner cylinder

Examples of troubles due to insufficient information,

during shutdown. This happened because there was noincorrectinstallation, etc. will be outlined, as mentioned

information about the mounting direction and negativeabove.

pressure. If powder accumulates between the cover andinner cylinder, it will affect the absorption ofset bolt

displacement of the cover, and the powder will scrape
against the cover during displacement, leading todamage to the cover.

bracketCountermeasures include filling the gap between theinner cylinder and the cover with heat insulating
material or installing both inner cylinders in order toeliminate the gap where fluid can enter.

Figure5 Half-sectional view of XP-221 equipped with a set bolt

In operation

After stopping4-1）Omitting removal of set bolts

Protection Sheetmaintain the structure of the product during

Cover
Inner canistertransportation and storage. Although instructions aregiven to remove the set bolts when the product isinstalled, it may happen that the product is operated

Fall by gravity

FlangeFlow direction

bolt is shown in Figure5. Set bolts are installed toGasket

Flangewithout removing them. Since the primary role ofexpansion joints is to absorb displacement throughexpansion and contraction, it is pointless to leave theFigure6No.41

Image of the XP-221 with inner cylinder during
shutdown

rigid set bolts in place.
Occasionally, mounting is done with the bolts slightlyloosened, but the maximum displacement cannot be

Summer 2021

A half-sectional view of the XP-221 equipped with a set4-3）Installation of thermal insulation on theoutside of the productabsorbed with the set bolts in place, so they must be

Although we do not recommend the application ofremoved after the product is installed.

thermal insulation to the product, there have been

In principle, we make sure that the removal of the set

cases where it was wrapped around the expansion

bolts is clearly indicated on the delivery drawings

joint as well, in order to maintain thermal efficiency ofprovided by our company.

the equipment. Figure7 shows a half-sectional view of
the XP-221 equipped with thermal insulation. When4-2）D ust accumulation problem due toinsulation is applied, heat from the fluid is trappedinsufficient information regarding

without hardly being dissipated to the outside air.

mounting position

Wrapping insulation around can lead to a loss ofNormally, if there is no specific instruction, the productelasticity and heat-induced deterioration of the cover,is designed to be installed parallel to the ground. In thiseventually damaging the product. If thermal efficiency

example, the design included an inner cylinder because

is a priority, shortened product lifetime and damage

the fluid was powder. Figure6 shows an image of themust be considered in advance.
4Precautions when considering usage and troubleshooting（FlectorTM）

As a countermeasure, considering outside installation,
CR tarpaulin, which has good weather resistance, was5. Precautions for usage

selected as the most outmost layer, but since its heat

As mentioned above, it is possible to design theresistance is low, in this case, we applied a cover madeproduct if the pink sections in Figure4 are provided.

of heat-resistant inorganic cloth and PTFE film.

However, since troubles such as those mentioned above

Temperature
25℃

Heat insulator

may occur due to insufficient information, it isimportant that we proactively confirm and obtain
detailed information from our customers. Even so,
installation problems are more common than otherproducts, and since the installation is done by thecustomer, particular attention should be paid to thefollowing:

FluidDucttemperature
300℃

CoverThermal insulation

Figure7 H
 alf-sectional view of XP-221
equipped with thermal insulation4-4）M alfunction due to insufficient information
on current condition of installed equipment

Summer 2021
No.41

1）S
 et bolts are to be removed after the product is installed.
2）I f the product is equipped with an inner cylinder,
consider the flow direction, and do not reverse theinstallation.
3）D o not wrap with thermal insulation.

There has been a case where, due to long-term use of
the equipment, earthquakes, and aging, there weredeviations between the information in the6. Conclusion

documentation when the equipment was first installed

The FlectorTM introduced in this report is a productand the current situation, leading to mounting defects

directly related to the safe and secure operation of aand damage after operation. In addition, sometimes theplant, so it is necessary to design the product carefully.

distance between the surfaces becomes longer, or theIn order to do so, sufficient information is indispensable,

bolt positions are shifted by several degrees. Since suchand we intend to make use of our long years ofdeviations are not taken into account in the design,

knowledge to proactively conduct extensive hearings

there are high chances that the equipment will beand propose solutions.

damaged after operation even if it can be installed, andthus it is crucial to verify the current conditions.

Takanori Sakamoto
H&S Sales Div.
Technical Solutions Group
Technical Paper
5※ "Flector" is a trademark of VALQUA, LTD.