Flow Meter & Monitor

Quick couplings

The Nitto Kohki Flow Meter & Monitor range covers flow measurement and monitoring instruments for pneumatic systems, made of brass with FKM seals (FMC types) or without seal (FM types). The range includes the compact FM-03B, the FMC-30-3F and FMC-30-4F monitors for nominal sizes 3 and 4, plus accessories such as FlowVane and Stopper for the FMC-30 system. These instruments allow monitoring and documentation of air consumption and leakage in compressed-air installations.

⚙ Brass construction - suitable for dry and oil-mist compressed air

✦ FKM seals (FMC types) - enhanced chemical resistance of the measuring head

✓ Nominal sizes 3 and 4 (FMC-30) - FMC-30-3F and FMC-30-4F for different line diameters

⬡ FlowVane and Stopper accessories - extensions for the FMC-30 measurement system

↕ Compact FM-03B - small-format flow meter for restricted installation spaces

Type	Function	Nominal size	Material	Seal
FM-03B	Compact flow meter	-	Brass	-
FMC-30-3F	Flow monitor	3	Brass	FKM
FMC-30-4F	Flow monitor	4	Brass	FKM
FlowVane for FMC-30	Vane wheel accessory	-	-	-
Stopper for FMC-30	Stop accessory	-	-	-

Typical applications: Leakage monitoring and energy efficiency analysis in stationary compressed-air networks, air consumption measurement at individual machines and tools, quality assurance in pneumatic manufacturing processes, and consumption documentation for energy management systems to ISO 50001.

Technical data from the manufacturer catalogue

Series	FLOW MONITOR
Body material	Brass
Seal material	Fluoro rubber (FKM)
Max working pressure	1.0 MPa {10 kgf/cm2}
Working temperature	Fluoro rubber (FKM): +10 °C to +80 °C
Applicable fluids	Water
Size range	Rc 3/8 and Rc 1/2
Catalogue page	C01en-b, 166

Operating principle

Connecting sequence of a ball locking quick connect coupling.

Fluid flow from low flow rate (2 L/min) water pipes can be visually checked with the rotating two-colored impeller.
Flow Vane ASSY can be replaced without removing it from the piping.
The stopper prevents unintended removal of the plastic parts.
Installation and replacement is easy since the screw part of the T2 side rotates freely to the left and right.
The Flow Vane ASSY can be replaced when dirty.
Fluid flow can be bi-directional.
RESIDUAL PRESSURE RELEASE JIG: residual pressure within socket or plug can be released easily by just turning the handle.
RESIDUAL PRESSURE RELEASE JIG: jigs are available in two types, socket type for use with plugs and plug type for use with sockets; connection to sockets or plugs is the same as connection of a normal CUPLA.

All models of the series

FMC-30 - Female thread

Model	Coupling part	Application	Brass (g)	L	A	T	øH1 (WAF)	øH2 (WAF)	øøD
FMC-30-3F	flow monitor	R 3/8	167	(81)	(40)	Rc 3/8	Hex.24	Hex.21	30
FMC-30-4F	flow monitor	R 1/2	256	(94)	(40)	Rc 1/2	Hex.29	Hex.29	32

BH-M - Male thread

Model	Coupling part	Application	Brass (g)	L	T	øH1 (WAF)	øH2 (WAF)	øøB
BH90-3M	adapter	Braided hose ø9×ø15 mm, hose wall thickness 3+/-0.3 mm, size 3/8 inch	106	(49)	R 3/8	Hex.23	Hex.24	8.5
BH120-4M	adapter	Braided hose ø12×ø18 mm, hose wall thickness 3+/-0.3 mm, size 1/2 inch	159	(59)	R 1/2	Hex.27	Hex.27	11
BH150-4M	adapter	Braided hose ø15×ø22 mm, hose wall thickness 3.5+/-0.35 mm, size 1/2 inch	210	(67)	R 1/2	Hex.30	Hex.30	13
BH190-6M	adapter	Braided hose ø19×ø26 mm, hose wall thickness 3.5+/-0.35 mm, size 3/4 inch	301	(74)	R 3/4	Hex.35	Hex.35	17

PART

Model	Coupling part	Application
CB66137	Flow Vane ASSY (plastic part) for FLOW MONITOR	Replacement Flow Vane ASSY
CB67052	Inner sleeve for FLOW MONITOR	Replacement inner sleeve
CQ48710	Stopper for FLOW MONITOR	Replacement stopper

Dimensions in millimetres. Values in brackets apply in the connected condition.

Legend: L = overall length; H = width across flats or outside dimension; D = socket outside diameter; A = hose barb length; C = sleeve dimension; T = thread or barb size; B = bore

Series comparison

Series	Max working pressure	Size range	Valve structure	Applicable fluids
COMPACT ZEROSPILL CUPLA	10 bar	Thread 1/8 inch, 1/4 inch	Two-way shut-off (Spill Reduction)	Air, Water
CUPLA HOSE with FULL BLOW CUPLA	10 bar	Hose size ø5 mm×ø8 mm, ø6.5 mm×ø10 mm, ø8.5 mm×ø12.5 mm	One-way shut-off	Air
FLOW MONITOR	10 bar	Rc 3/8 and Rc 1/2	-	Water
ANTI-VIBRATION PLUG HOSE	15 bar	R 1/4 (SHA-3-2R), R 3/8 (SHA-3-3R)	One-way shut-off	Air
HI CUPLA BL	15 bar	1/4 inch, 3/8 inch, 1/2 inch (thread and hose barb); SN type for urethane hose: for 6.5 x 10 mm, 8 x 12 mm and 8.5 x 12.5 mm hose	One-way shut-off	Air, Water
HI CUPLA Two Way Type	15 bar	Thread 1/4 inch, 3/8 inch, 1/2 inch. Hose barb for dia. 6.5 mm x dia. 10 mm and dia. 8.5 mm x dia. 12.5 mm hose.	One-way shut-off	Air
FLATFACE CUPLA F35	350 bar	Thread 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch	Two-way shut-off (Spill Reduction)	Hydraulic oil
FLATFACE CUPLA FF	350 bar	3/8 inch, 1/2 inch, 3/4 inch, 1 inch (thread)	Two-way shut-off (Spill Reduction)	Hydraulic oil

Choose FLOW MONITOR when the task is to see whether water is actually flowing in a mold cooling line, not to connect or disconnect that line: the sibling series such as HI CUPLA BL, LOCK CUPLA 200 and ROTARY LINE CUPLA are one-way shut-off couplings and indicate no flow at all. Its use is limited to water at a working pressure of 1.0 MPa {10 kgf/cm2} and a flow range of 2 to 20 L/min with Rc 3/8 or Rc 1/2 female threads, so lines run at the 1.5 MPa of those one-way shut-off series are outside its rating. Where the concern is not flow indication but fluid escaping on disconnection, the two-way shut-off COMPACT ZEROSPILL CUPLA is the series to look at.

Body and seal materials

Body material
Brass

Seal material	Mark	Working temperature	Remarks
Fluoro rubber (FKM)	-	+10 °C to +80 °C	-

Further catalogue data

Note	Value
Pressure unit conversion	1.0 MPa = 10 kgf/cm2 = 10 bar = 145 PSI
Flow Vane ASSY material - outer cylinder	Polycarbonate
Flow Vane ASSY material - impeller	Polypropylene
Flow Vane ASSY material - inner sleeve, stopper	Polyamide
Maximum tightening torque Rc 3/8	12 Nm {122 kgf - cm}
Maximum tightening torque Rc 1/2	30 Nm {306 kgf - cm}
Flow direction	Fluid flow can be bi-directional.
Recommended replacement time of Flow Vane ASSY	Read from the chart on page 168: the recommended replacement time is calculated from the amount of wear on the internal parts of the Flow Vane ASSY based on long-term flow durability tests; chart axis values 1000 to 100000 h with 5500 h and 14000 h marked and flow rates of 10 to 30 L/min.
CUPLA ADAPTER for Braided Hose Connection - body material	Brass
CUPLA ADAPTER for Braided Hose Connection - working pressure	Depends upon the specifications of braided hoses to be used.
CUPLA ADAPTER for Braided Hose Connection - working temperature range	Depends upon the specifications of braided hoses to be used.
CUPLA ADAPTER for Braided Hose Connection - applicable fluids	Air, Water, Oil
CUPLA ADAPTER for Braided Hose Connection - maximum tightening torque (taper pipe threads)	BH90-3M 12 Nm {122 kgf - cm}, BH120-4M 30 Nm {306 kgf - cm}, BH150-4M 30 Nm {306 kgf - cm}, BH190-6M 50 Nm {510 kgf - cm}
RESIDUAL PRESSURE RELEASE JIG - model naming	ZN - type of CUPLA to be attached. Example: for CUPLA model 350-3S the jig name would be ZN-350-3S.
RESIDUAL PRESSURE RELEASE JIG - attachable CUPLA	Sockets and plugs for SP CUPLA Type A, HSP CUPLA, 210 CUPLA, S210 CUPLA, 280 CUPLA and 350 CUPLA
RESIDUAL PRESSURE RELEASE JIG - sales unit	1 pc.
Flow rate	Working flow range 2 to 20 L/min. Flow rate - pressure loss characteristics chart on page 168 for FMC-30-3F and FMC-30-4F. Test conditions: fluid water, temperature 23 deg C. Chart range 1 to 100 L/min against 0.0001 to 0.1 MPa {0.001 to 1 kgf/cm2} pressure loss.

Interchangeability and size groups

The CUPLA ADAPTER for Braided Hose Connection mounts on a CUPLA plug or socket with female thread, such as ZEROSPILL CUPLA and SP CUPLA Type A. The RESIDUAL PRESSURE RELEASE JIG attaches to sockets and plugs of SP CUPLA Type A, HSP CUPLA, 210 CUPLA, S210 CUPLA, 280 CUPLA and 350 CUPLA.

Safety and application notes

RESIDUAL PRESSURE RELEASE JIG caution: since the upper limit of residual pressure that can be relieved depends on the product, please contact us separately.
Semi standard items: as these items are not always in stock, delivery time is subject to confirmation.
When ordering, please indicate Model Name or part number.

All technical data on this page is taken from the Nitto Kohki general catalogue Quick Connect Couplings C01en-b, page 166. The complete catalogue is available for download on this page.

What are pneumatic flow meter monitors and where are they used in industrial applications?

Pneumatic flow meter monitors are precision instrumentation devices that measure and display real-time fluid flow rates in compressed air systems, incorporating quick-connect couplings for rapid system integration. These devices serve critical roles in manufacturing automation, quality control processes, and pneumatic conveying systems where accurate flow measurement ensures consistent production output. Industries including automotive assembly, food packaging, pharmaceutical manufacturing, and semiconductor fabrication rely on these monitors to maintain ISO 9001 quality standards and optimize compressed air consumption efficiency.

What technical specifications should I consider when selecting a Nitto Kohki flow meter monitor?

Critical selection criteria for Nitto Kohki flow meter monitors include operating pressure range typically spanning 0.1 to 1.0 MPa, port diameter compatibility with standard pneumatic fittings from 1/8 inch to 1/2 inch, and material construction such as brass bodies with FKM seals for chemical resistance. The FMC-30 series models feature brass construction with FKM elastomer seals rated for temperatures from -10°C to +80°C, while flow measurement accuracy typically maintains ±3% of full scale reading. Media compatibility extends to compressed air, inert gases, and non-corrosive fluids with particle filtration requirements of 40 micrometers or finer to prevent internal mechanism damage.

Which international standards and certifications apply to pneumatic flow meter monitors?

Pneumatic flow meter monitors must comply with ISO 8573 compressed air quality standards for contamination levels and ISO 4414 pneumatic fluid power general rules for safe operation up to 1.6 MPa working pressure. European installations require conformity with EN 983 safety requirements for fluid power systems and components, while ATEX Directive 2014/34/EU certification becomes mandatory for explosive atmosphere applications in chemical or grain handling facilities. Additional compliance with IEC 61010 electrical safety standards applies to models incorporating electronic displays or signal outputs, ensuring protection against electrical hazards during maintenance operations.

What are the differences between FMC-30-3F and FMC-30-4F flow meter monitor variants?

The primary distinction between Nitto Kohki FMC-30-3F and FMC-30-4F variants lies in their port configuration and flow capacity ratings, with the 4F model typically featuring larger internal passages for higher volume applications up to 400 L/min compared to the 3F model's 300 L/min maximum flow rate. Both models utilize identical brass construction with FKM seal materials for chemical compatibility, but differ in their quick-connect coupling geometry to accommodate varying pneumatic line sizes and pressure drop requirements. The numerical designation directly correlates to maximum flow measurement capability, allowing system designers to select appropriate capacity margins for their specific compressed air consumption profiles.

What installation requirements and connection types are needed for pneumatic flow meter monitors?

Installation requires straight pipe runs of minimum 5 times the pipe diameter upstream and 2 times downstream from the flow meter monitor to ensure accurate measurement, with ambient temperature stability between 0°C and 50°C for optimal performance. Nitto Kohki quick-connect couplings utilize standard pneumatic thread connections including G1/8, G1/4, and G3/8 BSP parallel threads, with push-to-connect variants available for rapid system integration without thread sealant. Proper installation orientation maintains the flow direction arrow alignment with system flow, while pressure relief valves upstream prevent damage from pressure surges exceeding the monitor's 1.0 MPa maximum rating during system startup or shutdown cycles.

What safety ratings and operating conditions apply to pneumatic flow meter monitors?

Pneumatic flow meter monitors typically carry IP65 ingress protection rating against dust and water jets, enabling installation in harsh industrial environments with exposure to cutting fluids or wash-down procedures. Operating temperature range extends from -10°C to +80°C for brass construction models with FKM seals, while maximum working pressure reaches 1.0 MPa with 4:1 safety factor burst pressure testing per ISO 4414 standards. Electrical versions incorporate Class II double insulation rated for 24V DC operation with intrinsic safety barriers required for hazardous area installations, ensuring compliance with ATEX Zone 1 explosive atmosphere requirements in chemical processing applications.

What maintenance intervals and service life expectations apply to pneumatic flow meter monitors?

Routine maintenance intervals for pneumatic flow meter monitors require visual inspection every 3 months for seal integrity and flow indicator functionality, with complete disassembly and seal replacement recommended annually in high-duty cycle applications exceeding 8 hours daily operation. Service life typically extends 5 to 7 years under normal industrial conditions with proper filtration maintaining compressed air quality per ISO 8573 Class 3 standards, while harsh environments with temperature cycling or chemical exposure may reduce operational life to 3 years. Calibration verification against certified reference flow meters should occur every 12 months to maintain measurement accuracy within ±3% tolerance, with replacement indicators including erratic flow readings, visible seal deterioration, or internal contamination affecting measurement stability.