Technology

Cautionary points (Rubber flexible joints)

ATTENTION

Rubber flexible joints Cautionary points

Please make sure to observe the following Cautionary Points for safe use and making the most of our rubber flexible joints (products mentioned below).

Cautionary points during use

  • 1.Check to see if there is any damage to the product before use. Do not use the product if there is any damage in the packing surface, inner/outer rubber surfaces, etc.
  • 2.Usage range
    Make sure that the on-site maximum working pressure and maximum working temperature are within the usage range of each product before use. Any use outside the usage range may significantly shorten the life of the product and may cause problems such as liquid leakage.
  • 3. Correcting complex displacement amounts
    The allowable displacement amount for each product is the maximum standalone displacement value. Therefore, if there are complex displacements, they must be corrected using the following formula.
    (E.g.) corrected permissible expansion amount in case of TOUGHLEX 100A requiring an eccentricity of 10mm
    Corrected expansion amount = 15×{1-(+)}=7.5mm
  • 4.The product may be damaged by erroneous operation such as shut-off operation; please check the open/close state of the valve when operating the product.
  • 5.Use sufficient caution to avoid valve operation that allows sudden liquid flow.
  • 6.We recommend using the product below with an in-pipe flow rate of 3m/s or less.
  • 7. Use caution not to allow oils and fats, organic solvents (paint thinner, toluene, etc.), acids, alkalis, etc. to come into contact with the product.
    Please wipe off immediately if it happens
  • 8.When using air to test the pressure resistance of piping lines, please do so after detaching joints. If carrying out a test with joints attached, use liquid pressure instead of air pressure.

Cautionary points during storage

  • 1.Use sufficient caution not to damage the product in transportation or storage. Please do not use the product if it is damaged.
  • 2.When storing the product for an extended period, place it in a cool, dark place out of direct sunlight.
  • 3.Please do not leave the product for an extended period in a location with a temperature of 40 degrees Celsius or more, excessive humidity, or moisture.
  • 4.Use sufficient caution not to expose the product to fire.
  • 5.Use caution not to apply load to the product.

Cautionary points during installation

    • 1.See the diagram below when determining a pump installation location of the product. If a check valve is attached to the upstream side (the side closer to you) of the product, a fault may occur due to constant head pressure causing accumulation of fatigue, or from water hammer caused by starting/stopping the pump.
      Also, if piping the product directly to the gate valve (butterfly valve), the packing surface may be damaged, so it is recommended to install through a short pipe.

      製品をポンプに取り付ける位置
      Number Name
      Fixing hardware (vibration isolation)
      Support hardware (vibration isolation)
    • 2.The product should be installed such that the installation dimensions are within permissible values including expansion, contraction, eccentricity, and deflection.
縮み・伸び・偏角・偏心イメージ画像
Number Name
Including expansion
Contraction
Eccentricity
Deflection
    • 3.Install the product such that it will not be in contact with any structure or device nearby (especially sharp corners) in the event of displacement.
    • When connecting a rubber flexible joint to piping, use accurate dimensions and centering so as to avoid unnecessary external force (compression, tension, twisting, etc.) being applied.
    • If, after installation, any welding or fusing is carried out near the installation, protect the product with a cover etc. to avoid exposure to sparks. Moreover, if there is a possibility of heat from welding or fusing reaching the product, please take measures such as removing it.
防護イメージ
Number Name
Welding location
Protective cover
  • 6.Although there are no quality-related problems over the deterioration of external rubber parts in outdoor piping, we recommend attaching lagging if there are any concerns about preventing deterioration.
ラギング取付けイメージ画像
Number Name
Lagging

Cautionary points when connecting

When attaching flanges

    • 1.When using a rubber flexible joint, the packing seal surface of the rubber body may be damaged depending on the shape of the flange it is connected to. Please refer to the table below to check the shape of your flange.

Flange type(Gasket face types)
Flat face(FF) Raised face(RF) Channel type(GF) Channel type(TG-T)/
Spigot-and-recess shape(MF-F)
全面座FF
平面座(RF)
溝形(GF)

①Gasket

溝形(TG-T)/はめ込み形(MF-F)
No issues

A sufficient amount of force
is available to hold down
the packing of the rubber body.
However, there is a risk of
damage to the packing surface
from welding burrs.
Please remove the burr using a file,
sandpaper, etc.,
and also use gaskets made
from materials other than
rubber (such as sheet packing)
as necessary.

No issues

Because the packing surface
of the rubber body and the diameter
of the companion flange seat
are approximately the same,
a sufficient amount of force
is available to hold down the packing.
However, when a coating
such as a PVC lining is applied,
a level difference with
the companion flange may occur due
to the coating.

Because this creates a risk
of damage to the packing surface,
also use gaskets made from materials
other than rubber(such as sheet packing)
as necessary.

No issues

Please also use gaskets
made from materials other than
rubber (such as sheet packing)
between the packing surface
of the rubber body and the
companion flange.

When directly connected
to GF gaskets specifically
for GF flanges, sealing
performance will deteriorate
due to the double packing caused
by sealing surfaces
of equivalent materials.

Cannot be used

The packing surface
may be damaged because
of an increased load per unit
area due to the smaller contact
surface between the protruding
part and the rubber body’s

packing surface.

    • 2. Insert attachment bolts from the product side and tighten the nuts from the other side. We recommend fitting spring washers to prevent slackness for added safety. If insertion from the product side is not possible, insert continuous thread studs and bolts from the piping side. Use caution not to allow the end of a bolt to protrude excessively to the product side.
取付ボルト装着イメージ
    • 3.When tightening bolts, tighten them evenly in a diagonal pattern. See the remaining compression amount table below for the applicable amounts of tightening. Abnormal attachment such as uneven tightening may damage the product and can lead to problems.
    • 4.After attachment operation, the attachment bolts may become loose due to vibration of the pump. Please tighten the bolts again evenly in a diagonal pattern.
    • 5.When attaching the product, check to see if the flexible flange’s indentation (groove) and the rubber body’s packing part are correctly set.

Attachment bolt dimension table

六角ボルト

Hexagonal bolt
(JIS B 1180 coarse thread)

Nominal diameter PT CONNECTOR・OFLEX・TOZENFLEX
PURE JOINT・LINERFLEX(TypeA)
・ELBOFLEX(TypeA)
TOUGHLEX
BF CONNECTOR
TOUGHBOY
KINGFLEX 20 SILENTCONNECTOR
JIS5K JIS10K JIS20K JWWA 7.5K
(JISG3443-2)
JIS10K JIS20K JIS10K
20 M12×55L(4) M12×55L(4) M12×55L(4)
25 M16×60L(4) M16×65L(4) M16×60L(4)
32 M12×50L(4) M16×60L(4) M16×70L(4) M16×65L(4) M16×70L(4) M16×60L(4)
40 M12×50L(4) M16×60L(4) M16×70L(4) M16×65L(4) M16×70L(4) M16×60L(4)
50 M12×55L(4) M16×60L(4) M16×70L(8) M16×65L(4) M16×70L(8) M16×60L(4)
65 M12×55L(4) M16×65L(4) M16×70L(8) M16×65L(4) M16×75L(8) M16×65L(4)
80 M16×60L(4) M16×65L(8) M20×80L(8) M16×70L(4) M16×65L(8) M20×85L(8) M16×65L(8)
100 M16×65L(8) M16×65L(8) M20×85L(8) M16×70L(4) M16×65L(8) M20×85L(8) M16×85L(8)
125 M16×65L(8) M20×75L(8) M22×90L(8) M16×75L(6) M20×75L(8) M22×95L(8) M20×70L(8)
150 M16×70L(8) M20×80L(8) M22×95L(12) M16×75L(6) M20×80L(8) M22×95L(12) M20×75L(8)
200 M20×80L(8) M20×80L(12)
M20×90L(12)※
M22×100L(12) M16×80L(8) M20×80L(12) M22×100L(12)
250 M20×80L(12) M22×90L(12) M24×115L(12) M20×90L(8) M22×90L(12) M24×100L(12)
300 M20×80L(12) M22×90L(16) M24×115L(16) M20×90L(10) M22×90L(16) M24×115L(16)
350 M22×95L(16) M22×95L(10)
400 M24×100L(16) M22×95L(12)

※When the flange material on the other side is SS400, and 2 flat washers and 1 spring washer are used

※Please refer to Cautionary Points for Handling Rubber Flexible Expansion Joints regarding attachment bolts for LINERFLEX (C Type) and ELBOWFLEX (B and C Type).

S Remaining compression amount(mm)
Product name LINERFLEX
(TypeA)
TOUGHBOY
KINGFLEX 20 TOUGHLEX PT CONNECTOR
TOZENFLEX
ELBOFLEX
(Type A)
ELBOFLEX
(Type B・C)
LINERFLEX
(Type C)
PURE JOINT
BF CONNECTOR
(Up to 100A)
Nominal diameter
20A・25A 1 1 1 1
32A~80A 1 4 1 1~2 1
100A 1 4 1 1~2 8.5 1
125A 1 4 1 1~2 8.5 1~2
150A 1 4 1 1~2 13 1~2
200A 1 4 1.5 2~3 13 13
250A・300A 1 2 2 2~3 13
350A~450A 4 13

Installation example of screw connection

Based on the installation procedures of PT Connector S and TOZEN FLEX S, the cautionary points when connecting are as follows.

    • 1.Remove the attachment bolt and remove the flange A socket from the main body.
取付ボルトを外したイメージ画像
Number Name
Flange A
Socket
Main body
    • 2. Pass flange A through the partner pipe. Check the orientation as you do so.
フランジ取付イメージ画像
Number Name
Pipe
Main body side.
    • 3.Check that the piping side screw is not damaged and the surface is smooth.
    • 4. Wrap seal tape (or sealing material) on the piping side screw and tighten the socket as much as possible by hand. Use a spanner (or wrench) on the socket and a wrench on the piping side, and tighten sufficiently.
フランジ取付イメージ画像
    • 5.Insert the attachment bolts from the rubber flexible joint side and tighten the nuts from the other side.
フランジ取付イメージ画像
    • 6.When tightening the attachment bolts, tighten them evenly, referring to the following remaining compression amounts for the tightening amount.
フランジ取付イメージ画像
Number Name
Flange A
Attachment bolt
Socket
S=Remaining compression amount
1.5A~25A(3~3.5mm)
32A.40A(4~4.5mm)
50A(5~5.5mm)
Pipe side
Main body
  • 7.Repeat steps 2 to 6 on the opposite side.
  • 8.After attachment operation, the attachment bolts may become loose due to vibration of the pump. Please tighten the bolts again evenly.

Installation example of screw connection

ねじ込み接続の施工例

Securing pipes –

    • 1. Reaction force is generated due to the internal pressure load in rubber flexible joints. To make most of the product’s performance, please fix the piping securely, referring to the reaction force values of the product.
ポンプ回り防振システム例1
ポンプ回り防振システム例2
Mark/Number Name
(A) Figure 1 Example of vibration isolation system around pumps
(B) Figure 2 Example of vibration isolation system around pumps
Fixing hardware (vibration isolation)
Support hardware (vibration isolation)
Hanger (vibration isolation)
    • 2. When fixing the piping, please refer to the reaction force values (axial reaction force during change in internal pressure) of the diagram below.
トーゼンフレックス、タフボーイ反力値
トーゼンフレックス、タフボーイ反力値

Mark/Number Name
(A) TOUGHLEX
(B) PT CONNECTOR
(C) TOZENFLEX
(D) TOUGHBOY
Axial reaction force[N]
Pressure
  • 3.If, unavoidably, pipes cannot be installed sufficiently securely due to the site conditions, we recommend a control unit (extension preventer). Furthermore, there may be times when the allowable displacement of each product is lower than the value displayed due to its size.

BP (Back Plate) type

Bracket type which uses the flange bolt holes on the partner pipe

取付ボルト締付け画像
Number Name
When rubber bushes are attached
  • Control unit BP (Back Plate) type Please refer to the table below regarding attachment bolts

Control unit BP (Back Plate) type Attachment bolt dimension table

Applicable products

TOUGHLEX・TOUGHBOY
BF CONNECTOR・PT CONNECTOR
TOZENFLEX・LINERFLEX(Type A)
KINGFLEX 20

六角ボルト

Hexagonal bolt (JIS B 1180 coarse thread)

Nominal diameter Applied flange
JIS10K JIS20K
32 M16×80L M16×90L
40 M16×80L M16×90L
50 M16×80L M16×90L
65 M16×90L M16×90L
80 M16×90L M20×100L
100 M16×90L M20×105L
125 M20×100L M22×110L
150 M20×100L M22×115L
200 M20×105L M22×130L
250 M22×110L M24×150L
300 M22×120L M24×150L
350 M22×125L
400 M24×130L

※When the flange material on the other side is SS400

W Type (Welding)

Type in which the bracket is welded directly to the product flange

取付ボルト締付け画像

Thermal cutting Type

Type which the bracket is integrated with the product flange

取付ボルト締付け画像
Number Name
When rubber bushes are attached

Display of date of manufacture

The date of manufacture is displayed on the main body rubber as shown on the diagram below.
(E.g.) When manufactured in May 2013

製造年月の見方
Number Name
Month
Year
Year manufactured
Month manufactured

Service life

Rubber flexible joints are compound elastic bodies comprised of rubber and reinforcing layers. They are not permanent and have limited service life.
Product service life is significantly influenced by various factors, therefore it is not possible to definitely state the number of years it can be used.
We believe the standard service life under average usage conditions is as follows:

1)Standard service life – approx. 8 to 10 years (when used under average usage conditions as stated below)

Average usage conditions
(TOUGHLEX・PT CONNECTOR・TOZENFLEX・TOUGHBOY etc)

  • Working temperature・・・・・・Ambient temperature(0~40℃)
  • Working pressure・・・・・・・Approx. 1.0MPa {10.2kgf/cm2}
  • Start/stop frequency・・・・・10 to 20 times/day
  • Operating time・・・・・・・・No more than 10 hours/day
  • Installation condition・・・・・Must be in a piping state in which no force is applied thanks to correct centering and it is supported correctly.

The above standard service life changing significantly due to various factors including installation condition, displacement load, operating hours, etc. cannot be avoided. Please be aware that the given value is for reference only.。
Furthermore, please conduct maintenance and inspection to determine the service life of the product accurately and to prevent any accidents.

2)Factors shortening service life

Please be aware that the service life of products will shorten due to the following factors.

  • When used over an extended period of time at pressures extremely close to the product’s maximum working pressure value
  • When used over an extended period of time at temperature values extremely close to the product’s maximum working temperature
  • When the number of hours used per day exceeds 10 hours by a significant amount
  • When used with repeated displacement movement
  • When the pump start/stop frequency exceeds 20 times per day by a significant amount
  • When used with marked pressure fluctuations of 1.5 times or more (maximum working pressure ←ー→ standard working pressure)
  • When used with various displacements reaching the maximum level for the product

Maintenance and Inspection

Rubber flexible joints vary in service life depending on the usage conditions. Problems such as liquid leakage will occur during usage after service life. Please be sure to conduct maintenance and inspection for early detection of problems and abnormal installation state of the products. Please refer to the manual provided with the product for inspection intervals and overview. Please be sure to store the manual in a safe place.。