・ FLO-PL4 type, FLO-PL18 type
・ FLO-I-18 type, FLO-I-12 type
・ FLO-L65 type, FLO-L68 type, FLO-L70 type, FLO-L70 type (double type)
・ MS-33 type (triple type)

1. Dirt in the tapered tube
2. Float movement
3. Leakage of fluid seal part
4. Corrosion of parts in contact with fluid
5. Corrosion / deformation of float
6. Changes in measurement conditions such as temperature and pressure

Item	Content	Criteria
Inflow / outflow connection	Airtightness Installation method	・ No leaks ・It must be installed vertically on the pipe.
Tapered pipe part	① Airtightness of packing gland ② Dirt on the inside and outside ③ Dirt / peeling of flow rate scale ④ Internal and external scratches	・There is no leakage. There should be no corrosion or aging of the packing. ・It is not dirty. ・Clear without dirt or peeling. ・No scratches or cracks.
Strut	①Looseness of the strut tightening nut ②Rust on strut and nut	・There should be no looseness or bending of the strut. ・No rust
Float	①Corrosion ②Fluid sticking ③Wear / deformation of the edge of the maximum diameter brim ④Clogged guide hole ⑤Deformation, weight change, specific gravity change	・It is not corroded. ・No liquid debris or dust is stuck. ・There should be no wear, deformation or scratches on the edges. ・There is no clogging of the hole. ・The float specific weight does not change.
Float guide	①Corrosion ②Bend ③Set position ④Adhesion of fluid ⑤Float stopper	・It is not corroded. ・There is no bend. ・Always set in the center of the tapered tube. ・No fluid dust is attached. ・There is no corrosion or deformation of the stopper.
	Zero point	When no fluid is flowing, indicate 1/10 or less of full scale.
	Safety	Instructions are stable.

1. Select a place with less vibration for installation. Also, select a space that is easy to replace and clean the float and other parts.
2. Install so that the central axis of the tapered tube is vertical. If the central axis of the tapered tube is tilted with respect to the vertical line, the accuracy and sensitivity of the flow meter will decrease, so be careful about the verticality of the rising pipe and the levelness of the mounting surface.
3. Provide a bypass pipeline so that even if the flow meter is removed for repair or maintenance, it will not affect the operation of the equipment.
4. Fix the piping so that the stress generated in the piping system is not transmitted to the flow meter.
5. Since the movement of the float may become unstable, avoid sudden expansion or squeezing of the diameter immediately before the inflow part or immediately after the outflow part.
6. Open and close the valve gently to avoid a sudden impact on the flow meter. (FLO-PL18 type / FLO-L68 type)
7. Be careful not to give a sudden temperature change to the tapered tube (hard glass).
8. Please note that fluids containing foreign substances may cause malfunctions.
9. When suspending winter operation to prevent damage due to freezing of the fluid, drain the liquid or keep it warm.
10. Dirty taper tube

The flow measuring part of the variable area type flowmeter has a tapered tube installed vertically on the pipeline and a float (movable part) that moves up and down in the tapered tube. Then, the fluid enters from the bottom of the tapered pipe and flows out upward.

When the fluid starts to flow, a differential pressure is generated before and after the float, and the float moves up and down. At this time, the area of the annular part created between the float and the tapered tube and the flow rate are in a proportional relationship.

As the flow rate increases, the float moves upward and the annular area increases, balancing upward forces (front-back differential pressure, fluid buoyancy and float surface friction, etc.) with downward forces (float weight). At the position, the float is stationary. The instantaneous flow rate value is measured by directly or indirectly detecting the position.