SIMPLE, BUT RELIABLE
BEST COST PERFORMANCE

R-100 Series
GLASS TUBE FLOWMETER

GENERAL
R-100 is a glass tube type variable area flowmeter. The flow rate isindicated by the position of float and the graduation engraved on theglass tube.
Although it has a very simple construction, it is widely used for measurement of flow rate of liquids and gases in various applications
thanks to its high reliability and easy handling capability.

R-700 series having alarm contact are also available. (Refer to separate TECHNICAL GUIDANCE for details.)

FEATURES❏ DIRECT OBSERVATION OF FLUID
In addition to flow rate measurement, direct observation of fluid
can be done through glass tube. This is effective for quality control of process line.
❏ COST EFFECTIVENESS
This is the most cost effective device for local flow measurement.
Very widely used for various applications.
❏ EASY INSTALLATION
No adjustment is required after installation. No straight run for
upstream and downstream is needed. This results easy piping
design.

MODEL CODE

❏ EASY MAINTENANCE

R-10

Very simple construction offers almost "NO MAINTENANCELOAD".
❏ PURE MECHANICAL CONSTRUCTION
Flow rate is measured by pure mechanical action and no utility

Flow Direction

supply such as electric, air...required.

Description
1

BOTTOM → TOP

2BOTTOM → TOP SIDE

3

BOTTOM SIDE → TOP SIDE

4BOTTOM SIDE → TOP

5Options

BOTTOM REAR → TOP REARR

RIBBED TAPERED TUBEVFLOW ADJUSTING VALVE

TG-F2369-E01
2nd edition Jan 2024 K
1st edition Aug 2023 K

R-100 Series GLASS TUBE FLOWMETER

STANDARD MATERIAL PRODUCTSOUTLINE

DIMENSIONIn STANDARD MATERIAL PRODUCTS, the fluid contacting body

R-101

material is cast iron and stainless steel. They are widely used for

R-102

measurement of water, air and other "Not-so-corrosive" fluids.

R-103

R-105
AA

STANDARD SPECIFICATIONAll kinds of liquids and gases● Available size		

L(Not suitable for steam measurement. AM
series Metal Tube Flowmenters are recommended.)

LL● Measuring fluid		

10 to 100

(Meter size)● Process connection

Standard		 JIS 10K flange
Option		 ANSI, JPI, other flanges			Rc, NPT (up to 25mm)

Metersize

Max. Fluid press.
(MPa)

Metersize

Max. Fluid press.
(MPa)

101.2

500.6

151.0

65

0.6

200.8800.4250.8

1000.4400.6● Max. thermal shock		

80°C● Indication accuracy

Stainless steel float ±1.5%F.S.
Resin float±2.5%F.S.

● Range ability		

10:1Fittings		 SCS14, SUS304, SUS316
Tapered tube		 Heat-resistant glass (Acryl tapered tube isavailable on request.)
Float		 For liquids
SUS304, SUS316, SUS316L, PVC, Others			For gases
Aluminium, PVC, PTFE, SUS304, Others
Float rod		 SUS304, SUS316, SUS316L, Others(The meters for gases with 20 or more inmeter size and ones for liquids with 40 ormore have the float rods)
Packing		 NBR, FPM, Others● Paint		Not painted● Fluid temp		

Select the temperature for the material inthe following table in the operating temperature limit.

Float
Packing

7575100
100100120120
140140160＊Refer to the flow rating by size in the next page.

● Available material

Tapered tube

A (mm)

420420
430
500
500
500
530
530
570590PRODUCT MASS			 (±3% F.S. for liquids with QW of 50 L/h orlower, and gases with QA of 1.5 m3/h (nor)or lower)

Material
Heat-resistant glass
AcrylicMetalPTFE
PVC
NBR
EPDML (mm)1015202540(B)＊
40(A)＊
50
6580
100

Fluid pressure

Parts nameDimension

Meter size

0Meter size

Mass (approx.)kg

1015202540

345814

Meter size

Mass (approx.)
kg

50
65
80
100

18222941

Above table shows the approximate mass of R-101 made of metal.

50

Operating temperature limit
（℃）
60
70
80

It is general data, and the maximum temperature may change by terms of use and environment.
2TOKYO KEISO CO., LTD.

120

TG-F2369-E01

R-100 Series GLASS TUBE FLOWMETERCAPACITY RATING❏ For gas measurement❏ For liquid measurement
Water flow [L/h]Air flow [m3/ h (nor)]

Glass tapered tube
StainlessPVC,
steel float
PTFE float

Acryl tapered tube
StainlessPVC,
steel float
PTFE float

109 to 120

30 to 55

70 to 120

30 to 55

10

Not available

15410

230

40023015

Not available

65.4

Not available

6201040

700

1000

700

20

9.7 to 30

1815

9.7 to 30

18

Meter size

Meter size

Stainlesssteel float

Glass tapered tube
Aluminum
float
0.16 to 1.6

Acryl tapered tube
Stainless
Aluminum
PTFE
steel float
float
float
0.15 to 1.4 Not available
1.2 to 1.6251750

1100

1600

1100

2551302451

30

40 (B)

2500

1650

2500

1650

40 (B)

71

41

43

71

41

40 (A)

4400

3000

4200

3000

40 (A)

130

78

86

130

78

50

9100

6400

9000

6400

50

270

160

150

270

160

65

12100

9200

12000

9200

65

350

220

180

350

220

80

21000

15300

Not available Not available

80

Not available

360

340

Not available Not available

100

52000

42800

Not available Not available

100

Not available

820

980

Not available Not available

Flowmeters with stainless steel floats may suffer from hunting at fluid pressures
below 0.1 MPa.

FLOW RATE COMPENSATION CALCULATIONIn this TECHNICAL GUIDANCE ﬂow rate tables are indicated by ﬂow rate of water (Density 1.0g/cm3, Viscosity 1.0mPa·s) and by ﬂow rate ofair (0°C, 1 atm). Thus, in case the actual operating condition diﬀers from them, the following compensation calculation is required to obtain
ﬂow rate in such condition and then, tables are referred for size selection.
❏ Liquid measurement applicarions
ＱＷ

Ｑ❏ Gas measurement application

ρ（ρｆ－1）（ρｆ－ρ）ＱＡ

ＱＷ ：Conversion coeﬃcient
Ｑ ：Density of liquid to be measured [g/cm3]
ρ ：Density of water [g/cm3]
ρｆ ：Density of ﬂoat [g/cm3] (Refer to Float density table below)

SUS 304,316

7.9

MA-B (Equivalent to Hastelloy C) 9.24

MA276 (Equivalent to Hastelloy C) 8.94 Titanium

4.5

Calculation example
Density of liquid 1.4g/cm3
SUS316 ﬂoat (7.9g/cm3)
Full scale 1000 L/hＱＷ

ρ（273 ｔ）
0.1013 ｐ

ＱＡ ：Air converted ﬂow rate [m3/h (nor)]
Ｑ ：Flow rate of actual gas [m3/h (nor)]ρ ：Density of actual gas [kg/m3 (nor)]ｐ ：Operating pressure [MPa]ｔ ：Operating temperature [℃]Calculation example
C,
CO2 gas 1.977kg/m3 (nor), Op.press. 0.5MPa, Op.temp. 40°
Full scale 100m3/h (nor)ＱＡ

ρ（ρｆ－1）（ρｆ－ρ）

1000

Ｑ 0.0169

1.977（273 40）
0.1013 0.5
100 0.0169 32.08

100 0.0169

54.22 m3/h（nor）

1.4（7.9 - 1）
（7.9 - 1.4）1000 1.219 1219 Ｌ/ｈ
1000

LIMITATION OF FLUID VISCOSITY
Refer to the following figure in case of measurement of high viscosity
liquid. If the viscosity of liquids is lower than the viscosity curve on
the viscosity vs. flow rate graph below, flowmeters are manufactured
as a standard procedure. The flow rate tables in this TECHNICALGUIDANCE can be referred to only by density compensation. If theviscosity is above the curve, contact Tokyo Keiso for detailed investigation by our factory computer.
3530PROCESS CONNECTIONS FOR EACH SIZE
JIS 10K Flange
Metersize 10A 15A 20A 25A 40A 50A 65A 80A 100A
1015202540506580100
JIS 5K Flange
Metersize 10A 15A 20A 25A 40A 50A 65A 80A 100A
10152025*1 *140506580100

Viscosity curve
R-10025

Viscosity[mPa·s] 2015105RcMetersize 1/4 3/8 1/2 3/4101520251*1 20A and 25A are not available for meter size 40mm (2).

110TG-F2369-E01

50100500

1,000

5,000 10,000

50,000 (ℓh)

TOKYO KEISO CO., LTD.

3

R-100 Series GLASS TUBE FLOWMETERSPECIAL MATERIAL, CONSTRUCTION PRODUCTS
RIBBED TAPERED TUBE VERSION❏ OUTLINE

RIBBED TAPERED TUBE

Float is guided by rib construction inside of glass tapered tube.
No float rod is provided and they are suitable for measurement ofRibbedtaperedtube

liquids with certain solids. Also, the distance from inner surface tofloat is stable and relatively close, and observation of float is easierthan that of standard flat tapered tubes.

FloatStabilizer❏ STANDARD SPECIFICATION● Available size

(Meter size): 10, 15, 20, 25, 40(B), 40(A) and 50

Other specification is equal to that of STANDARD MATERIAL❏ CAPACITY RATING

Flow rate *Meter size

PRODUCTS.
Lined material also available.

Water (L/h)

Air [m3/h (nor)]

1060 to 150

0.9 to 1.715

390

5.8

2095015251650

2340 (B)2500

Not available

40 (A)

4200

58507500115* : Flow rates in the Water and Air columns are for stainless steel floats
and aluminum floats, respectively.

POLYSULFON TAPERED TUBE VERSION (R-101-SU)❏ OUTLINE❏ DIMENSION

R-101-SU employs Polysulfone made tapered tube which is durable and suitable for strong alkalines such as caustic soda. This isvery much suitable for caustic soda measurement application whereglass tube is not suitable due to anti-corrosion capability againstfluid. And also suitable for saturated brine lines.

⑥④⑥● Measuring fluid②①: Transparent liquids (Suitable for causticsoda and brine)● Available size

(Meter size)

L⑤❏ STANDARD SPECIFICATION

Meter size

: 25, 40, 50 and 80③● Process connection :JIS10K flanges (Other flanged on request)● Flow direction: Bottom to Top● Fluid press.

: Max. 0.5MPa● Fluid temp.

: Max. 100°C● Indication Accuracy :±3% F.S.

Dimension
MassL(Approx.)
(mm)
kg

25330

64036075036098040012❏ CAPACITY RATING

Material availability
No. Parts name

Material

1

Tapered tube

Polysulfone

2Float

PTFE, Titanium, Stainless steel, Others

3Body

PP, PTFE lined, Stainless steel

4Packing

EPDM, FPM

56Water flow rate (m3/h)
Connection
StainlessMeter size
Titanium
PTFE
sizesteel,float
float
float
0.7 to 1.25 0.6 to 1.1 0.5 to 0.95 20, 25, 40mm
2540

4.5

4

3.525, 40, 50mm

Packing follower SUS304

5098740, 50, 65mm

Column8024241565, 80, 100mm

SS400 (SUS304)

Options : ① Normal flow rate indication pointer② Optical alarm unit

4TOKYO KEISO CO., LTD.

TG-F2369-E01

R-100 Series GLASS TUBE FLOWMETER

R-105-RK and R-105-RKS PANEL MOUNT, FOR GASES❏ OUTLINE

R-105-RK and R-105-RKS are panel mount type glass tube flowmeter for gas measurement and very much suitable for monitoring ofinjection gas flow rate into furnaces. Ribbed tapered tube is used for stable indication even for low pressure gas supply line. Also, the pressure
drop is designed low to meet the requirement in such applications.

R-105-RK • R-105-RKS Basic Model CodeSeries
R-105-RKS -Metersize
AFloatConnection
Standardmaterialsize
ARA

Packing
materialN

Alarm
output00

Oil preventivetreatment
00: Not treated
1: TreatedWith orwithoutpointer0: Not provided
1: With 1 point
2: With 2 points

Pointer--Specialitem
00: w/o special item
Z: w/special item

-Alarmoutput-O : With alarm
L : Lower limit alarm - 1 point
H : Upper limit alarm- 1 point
HL : Upper and lower limit alarm
LL : Lower limit alarm - 2 points
HH : Upper limit alarm - 2 points

N : NBR
Packing
material F : FPM
E : EPDM
Z : Others
R-105-RKandR-105-RKS

A : Aluminum
Floatmaterial 4 : SUS304
6 : SUS316
Z : Others
Standard R : Rc
N : NPT
Z : Others

Standard material: Aluminum

Rc connection is our standard.
Corresponding with adapter (Male & Female)for other connection sizes

A : 3/8Connection B : 1/2
size
C : 3/4

Same diameter as meter size is standard.
Corresponding with accessories like adapter(male and female) in case of different connection
D: 1
E : 1-1/2 size from meter size
F:Metersize

A : 10
B : 15
C : 20
D : 25
E : 40F : 502Materials
Body : SCS14 (R-105-RKS)
Aluminum (R-105-RK)
Tapered tube : Heat-resistant glass with ribs
❏ STANDARD SPECIFICATION● Measuring fluid

MATERIAL
Parts name
Body
Tapered tube with ribs
Float
O-ringCoverFixtures
Cap

TG-F2369-E01

Model code
R-105-RK
R-105-RKS
Aluminum
SCS14
Heat-resistant glass
Aluminum
NBR
SPCC
SPCC
SUS304: Gases such as air, nitrogen, propane			 and butane● Available size
: 10, 15, 20, 25, 40 and 50(Meter size)● Installation: Panel mount: Rc● Flow direction: Bottom rear to Top rear● Fluid press: Max. 0.3MPa● Fluid temp. range: 0 to 120°C● Max. thermal shock : 80°C
● Indication accuracy: ±2% F.S.
(A pointer indicating normal flow rate
can be installed on request)● Alarm contact: Available on request, 1 or 2 points
Contact		SPST, selfe-holding Reed switch
Setting accuracy		 ±2% F.S. Adjustable (Against flow calibration)
Reset span		Max.15% F.S. (Against flow calibration)
Enclosure		Water tightWiring		Direct connection to reed wire
● Paint		Metallic silver
TOKYO KEISO CO., LTD.
● Process connection

5R-100 Series GLASS TUBE FLOWMETEROPTIONAL PARTS

Capacity rating and approximate pressure drop for local
indicator with aluminum float

Meter size
1015
20254050❏ PROTECTION COVERPressure drop(kPa)
0.8
1.0
1.2
1.2
1.2
1.8

Flow rate{Air, m3/h(nor}
0.9 to 1.7
1.8 to 5.8
3.6 to 15
11 to 23
23 to 58
55 to 115

Transparent PVC and steel plate are ready to protect tapered tube.
Specify if required.

❏ FLOW ADJUSTING VALVE
A valve for flow adjustment will be assembled onto flowmeter onrequest.

Capacity rating and approximate pressure drop for alarm
type with aluminum float

Meter size
101520254050

Pressure drop(kPa)

Flow rate{Air, m3/h (nor)}
Not available
5 to 7.5
7.3 to 17
14 to 28
34 to 85
57 to 130

1.6
2.4
2.5
2.0
2.0

ORDERING INFORMATION
Notify the following for order/inqury
Model

Full scale can be specified within the range of flow rates of

R-10■ - ■each size shown in above table with the rangeability 10:1.
Fluid name
DIMENSION

Density
Panel cut

Body

Viscosity
Press.

2-dTemp.
Full scale

AConnection rating ■JIS10RF■mm■Rc■inch■L

L1L(H)

Connection size		Material■Cast iron ■SUS304 ■SUS316■Other special (		)Special instruction, if any

4 - ∅h(W)2 - ∅D(B)

Cautions on the use of glass tube variable area flowmeters

MODEL R-105-RK
Dimension (mm)Metersize (H)L(B)(W)
10 452 53
50 38015 462 73
65 39020 476 83
75 40025 558 93
85 46040 616 103 95 490
50 670 143 135 520

D20253138
5365

Mass
Panel cut (mm)(approx.)
L1Ahkg24 35062.240 370
63.540 360
84.545 430
86.550 435
108.560 440
1016

Avoid the use of glass tube variable area flowmeters for the following
services.
1. Liquid services subject to impulse pressure in the process.
2. Secondary accidents might occur due to the breakage of glass insuch services :MODEL R-105-RKS
Dimension (mm)Metersize (H)L(B)(W)
10 446 38
47 38015 446 48
54 38020 468 53
62 39025 548 63
67 46040 600 73
82 48050 620 83
97 490CAUTION

D2025313853
65

Panel cut (mm)L1Ah20 320
830 320830 320830 380
1040 380
1040 380
10Mass(approx.)
kg

1.8
2.2
2.8
47
9.2

• Toxic fluids such as poisons, stimulant and narcotics• Flammable fluids• Explosive fluids
3. Gas handling process where breakage of glass might result in gas
leakage or scattering of glass fragments.
4. The installation places of the flowmeters where breakage of glass
might be caused by the accidents from the surrounding piping orequipment.
5. On-off operation where breakage of glass might be caused by thecollision of the float inside meter due to the abrupt change of flow.
6. Services where the heat shock by abrupt change of temperature isexpected.

6TOKYO KEISO CO., LTD.

TG-F2369-E01

R-100 Series GLASS TUBE FLOWMETER* Specification is subject to change without notice.

Head Office : Shiba Toho Building, 1 – 7 – 24 Shibakoen, Minato-ku, Tokyo 105 – 8558
Tel : +81-3 – 3431 – 1625 (KEY) ; Fax : +81-3 – 3433 – 4922
e-mail : overseas.sales@tokyokeiso.co.jp ; URL : https://www.tokyokeiso.co.jp
TG-F2369-E01

TOKYO KEISO CO., LTD.

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