Kofloc RK20T Series User manual

FJ400049E1
Created on 2021/12/20
Flowmeter
Instruction Manual
Thank you for your selection of “KOFLOC Area Flow Meter.”
Prior to use, read this manual thoroughly to ensure your new meter will work to its
fullest capacity.
Resin Flowmeter
Model RK20T Series

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Caution
This flowmeter is designed to control the flow under the
following conditions of use:
Max. working pressure: 0.7 MPa(G)
Working temperature: 10 to 65℃(No condensation)
The use of the flowmeter with fluids other than those described on
the flowmeter such as toxic gases and corrosive fluids or at
temperatures or pressures above the maximum allowable levels may
cause personal injury. Never use the flowmeter in such a manner.
Also note that if solenoid valves are installed before and after the
flowmeter and they are opened/closed under pressure, a rapid
velocity change may cause the float to jump up to break the acrylic
tube. Ensure that a rapid pressure change will not occur.
Foreword
Thank you for your selection of Model RK20T Series.
・The contents of the manual are subject to change without notice.
・The manual has been created meticulously. Should, however, you notice any
deficiencies, errors or omissions, you are kindly requested to notify us.
・The warranty period of this product is one (1) year after shipment.
・Failures attributable to KOFLOC which may occur during the warranty period will
be remedied free of charge.
・KOFLOC shall not be held responsible whatsoever for breakdown or trouble of
equipment which results from negligence of the precautions described in this
manual or using the product by methods other than the described procedures.

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1. Features
RK20T is a resin flowmeter designed to control AIR/N2(7 rates) and WATER (5
rates) by the same size. Compared with conventional metallic flowmeters, this
flowmeter is smaller and lower in cost. Two types, one with a valve and one without
a valve are available.
If you have questions about the flowmeter, please contact us.
2. Installation and Piping
2.1. Installation
The standard installation method of this product is panel surface mounting; the
joint connecting part is fitted to the opening of the panel from the front side and
secured with the included mounting nuts from the back side.
This product comes with two mounting nuts each on the top and bottom sides as a
standard feature. Remove one each on each side, insert the joint connecting part to
the opening of the panel and secure it with mounting nuts so as to sandwich the
panel. This is necessary to protect the body from damage due to load that is applied
when the nuts are tightened.
Accordingly, our mounting nuts of the flow meter side, you are requested to note
you do not overtighten to the body side. (Inside nuts do not need to be in close
contact with the flowmeter body completely, tightening torque is also acceptable by
hand tightening. It should be thank you less than the maximum 4N・m. Please be
fixed outside nuts on the panel at the recommended value in 6 ~ 15N・m torque .)
In addition, please refer panel processing dimension to drawing described below.
Install the flowmeter vertically to ensure accurate measurement of flow. Also
minimize vibration and pulsating flow. They will affect the measuring accuracy
adversely.

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2.2. Piping
To connect and disconnect piping joints, set a wrench (adjustable wrench) of size 17
at the joint connecting part (flats on the periphery: width across flats 17 mm) of the
flowmeter to secure it. (This is necessary to ensure that no load will be applied to
the body of the flowmeter.)
After laying piping, test the joint connections for leak. Install a filter on the IN side
to prevent foreign matter from entering the equipment. In the case of AIR/N2, use
dry gas only. Use the flowmeter in conditions where no condensation occurs.
When attaching a pipe joint, the joint connection of the flow meter and the entire
needle (or the internal flow stopper for the without valve model) may rotate. This is
because the connection joint is integrated with the needle (or stopper), and this
rotation is not an abnormal operation. Please be assured that this rotation will not
cause any leaks or performance problems.
Standard Specifications
(Panel surface mounting)
Options
(Panel flush mounting)
Options
( Panel surface mounting
－for panel mounting screws )
＊Mounting screws according to
the panel thickness, thank you to
be prepared by the customer.
IN
OUT
IN
OUT
IN
OUT

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3. How to Use
3.1. Basic rule
(1) Reading the flow rate
Small to medium flow region: Read the rate at the center of the ball float.
Large region: Read the rate at the uppermost position of the top-shaped float. The
tapered tube acts as a lens. Read the rate at the same level ( or at a right angle).
(2) Flow rate adjustment
In case of model RK20T, please adjust the flow rate by turning the handle of the
needle valve attached. The flow increases by turning it anticlockwise (open)
and decreases by turning it clockwise.
3.2. Precautions for use
(1) The fluids to use are limited as follows; gas is AIR /N2and liquid is WATER.
This product is made of resin. Never use it with corrosive fluids, toxic
gases/liquids and fluids/gases containing chemicals and in corrosive
atmosphere.
(2) The working pressure (IN side pressure) … Proof pressure: 0.7 MPa.
If the flowmeter is subjected to a rapid change in pressure due, for example, to
opening/closing of a solenoid valve or application of a pressure exceeding 0.7
MPa, the flowmeter may be damaged or broken. Ensure that a pressure
exceeding 0.7 MPa will never be applied.
Ball
center
Do not grip the body (ABS).
If it is gripped, it may be
broken.
Secure the joint connecting
part of the flowmeter with a
wrench (adjustable wrench).
Uppermost position
of top-shaped float

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Do not install solenoid valves before and after the flowmeter.A rapid change in
pressure may cause up/down motion of the float to damage the flowmeter.
(3) Model RK20T-V (with a valve) does not guarantee the zero stop. If the zero stop
does not work, never turn the valve in the closing direction by undue force. The
needle part may be damaged to disable flow control. If the zero stop is required,
be sure to install a stop valve before this product.
(4) Please note that when measuring the flow rate of water, the float may not stay
in a position, but may become unstable in some rare cases. If this happens, open
the flow control valve to cause the float to contact the top stopper and then
adjust the valve so that the float will gradually come down to the position. If the
float is still unstable, repeat the above operation again.
(5) This flowmeter is designed for simplified checking of flow. For more stable and
accurate flow regulation, an upper model such as RK1250 is recommended. In
particular, since AIR/N2: 0.5L/MIN spec & 1L/MIN spec and WATER:
25mL/MIN spec are minute flow regulation, the flow may be affected by
changes in temperature and pressure. For stable flow over long hours, an upper
model such as RK1250 is recommended.
4. Specifications －RK20T －
【Rated specifications】
Fluid
AIR / N2
WATER
Flow rate
0.05 ~ 0.5 L/min
0.15 ~ 1.0 L/min
0.5 ~ 5.0 L/min
1.0 ~ 10 L/min
2.5 ~ 25 L/min
5 ~ 50 L/min
20 ~ 100 L/min
2.5 ~ 25 mL/min
30 ~ 300 mL/min
100 ~ 800 mL/min
200 ~ 1600 mL/min
500 ~ 1800 mL/min
Accuracy
FS±6%
Max. working
pressure
0.7MPa(G)
Max. working
temperature
65℃
Materials in
contact with fluid
ABS, acrylic resin, SUS303, hard glass or SUS316, FKM, POM,
(SUS304)
Connection
Rc1/4
* The flow rates are indicated at 20℃of air (atmospheric pressure) and 20℃of water.

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【RK20T dimensions】
(Options：Panel flush mounting)
Panel cut
Panel surface mounting
(Mount with supplied
nuts)
Needle valve
RK20T-V only
Needle valve
RK20T-V only
Burring tap
Dedicated
mounting panel
(option)
Panel cut
Panel flush mounting
(Mount with dedicated
mounting plate)

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(Options：Panel surface mounting －for panel mounting screws)
5. Troubleshooting
* Float will not move:
Dust/dirt is sticking. Conduct purge with clean air or N2.
* Float moving is unstable:
Please check this comes from real flow rate deviation or not.
* The flow rate cannot be set:
1) Check dusts or particles getting inside the gap or not.
2) Check the piping for fluid leak.
3) Check the lack of inlet pressure.
6. Corrective Action and Repair
If the product fails due to a cause attributable to Kofloc within one year after it was
shipped, the failed product will be replaced with a new one when the failed product
is received by us. Please note that this product is basically not covered by our repair
policy and it is therefore requested that, as a general rule, a new product be
purchased should your product fail. This policy is based on the product concept of
low cost priority.
Panel cut
Panel surface mounting
(Mounting by use of
M4 screws)

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7. Storage
(1) The storage place must meet the following conditions:
・A place where the flow meter will not be wetted by rains or water.
・A place where the flow meter will not be subjected to vibration and impact.
・Temperature: 5 ~ 45℃
・Humidity: 5 ~ 90%RH
・A place where no corrosive gases are present.
(2) When the flow meter is not used, pack it and then store it.
8. Product Warranty Policy
Thank you for your continued support of KOFLOC products.
Unless specified otherwise in quotations, contracts or specifications when you place
orders for KOFLOC products, the following warranty policy will apply.
Warranty Policy:
①Warranty period
The warranty period is one (1) year from shipment, provided that the product is
used within the KOFLOC specification.
②Scope of warranty
If the KOFLOC product fails during the warranty period due to a cause
attributable to KOFLOC, KOFLOC shall, at its option and expense, provide a
replacement product or repair the failed product at the KOFLOC factory.
This warranty, however, shall not cover damages due to a cause not
attributable to KOFLOC; opportunity loss, lost profit, secondary disaster,
accident compensation suffered by the customer and damage to other
equipment and any other damages due to a failure of the KOFLOC product.
③Non-warranty
The warranty shall not apply to the following failures and damages even if they
occur during the warranty period:
①Failure due to misuse or improper repair or modification. (Failures
resulting from use under conditions different from the manufacturing
specifications are included.)
②Damage and failure due to dropping of the product after purchase.
③Failure due to fire, earthquake, flood, lightning or other natural disaster; or
riot, war or the like.
④Failure due to intrusion of foreign matter from piping.

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⑤Failure caused by a specific problem due to combination with other
incorporated equipment.
⑥Other failures and damages which are considered not attributable to
KOFLOC.
Please be aware that the warranty shall not cover opportunity loss suffered
by you or your customer or damage to other equipment or any other damages
due to a failure of the KOFLOC product.
URL：http://www.kofloc.co.jp