Kawaki FY-MA Flow Switch and FY-M Flow Meter, Compact Type

The down-sized SF type for lubricating oil and cooling water

The Kawaki FY-MA flow switch and its FY-M flow meter version are described by Kawaki as the down-sized SF type, with the same features as the SF and SA types. The instruction manual calls the FY a dynamic-pressure flow meter: a plate placed in the flow takes a force proportional to the square of the flow velocity, and the force is balanced against a spring to measure flow. It is used for cooling water and lubricating oil, and the FY-MA gives an electrical signal for a flow alarm when flow rises or falls.

The manual lists three advantages: it is well suited to opaque liquids such as lubricating oil, it can measure comparatively viscous fluids, and because a magnetic coupling joins the wetted part and the indicator there is no leakage path at all.

Technical specifications

How it works and how to set the contact

A damper fixed on a shaft turns by up to about 80 degrees under the flow pressure and rotates an internal magnet in the connecting section; an external magnet follows it and carries the pointer over the scale. The side plate fitted in the FY gives a nearly proportional relation between the pointer movement and the flow even though the plate force follows the square law. In the FY-MA a cam on the main shaft operates a micro switch, and the switch mount slides through about 80 degrees around the pointer shaft so the set point can be placed anywhere on the scale.

To change the contact, remove the case cover and glass, turn the pointer by hand to the set pointer and listen for the switch, loosen the contact adjusting screw, rotate the switch mounting plate to the new position and tighten again. Never move the switch or cam or bend the set pointer, and re-check that the contact operates at the chosen point.

Installation notes and selection

Install with the flow arrow on the body, flush the pipework, check that the flapper moves from the inlet side before fitting and open valves slowly, because sudden high flow can deform the flapper. The manual advises periodic dismantling and brushing of the measuring section for slurry-laden fluids and protecting indoor-type cases from rain. The English page states that for use pressure of 1.0 MPa or more the SF type for high pressure should be used instead, and for frequent vibration the earthquake-resistant SF type.

For an enquiry give the bore and flange or screw connection, fluid, temperature, flow range, contact rating and material. A totally waterproof IP67 version and an externally variable contact are available on request.

How the Kawaki FY-MA works

A damper plate sits in the flow and turns under the flow pressure against a spring. The turn moves an internal magnet, and an outside magnet follows it with the pointer. In the FY-MA a cam on the main shaft operates a micro switch. The switch gives the flow alarm when the flow rises or falls to the set point.

Where the FY-MA is used

• Cooling water lines
• Lubricating oil lines
• Opaque liquids
• Viscous fluids
• Flow alarm duty on machines

Selection checklist for the FY-MA

• Flow rate and scale
• Liquid and viscosity
• Line size
• Flange or screw connection
• Line pressure
• Liquid temperature
• Switch rating
• Waterproof option

Installation, commissioning and maintenance notes for the FY-MA

Fit the unit in the line with the flow arrow in the right direction. Wire the contact to the alarm circuit. Remove the case cover and glass to set the contact point. Turn the pointer to the set flow and fix the switch mount. Refit the cover and test the alarm.

Requesting a quotation for the Kawaki FY-MA

Please send the liquid, the flow range, the line size and the connection type. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

FY-MA flow switch

The FY-MA is the flow switch version.

FY-MA flow meter version

The FY-M is the flow meter version with an indicator.

FY-MA size class

It is the down-sized SF type.

FY-MA measuring principle

It is a dynamic-pressure flow meter.

FY-MA leak path

A magnetic coupling joins the wetted part and the indicator, so there is no leak path.

FY-MA bore range

The bore runs from 3/8B to 12B for the flange type.

FY-MA screw type

The screw type runs from RC3/8 to RC1-1/2.

FY-MA standard pressure

The standard pressure is 1.0 MPa.

FY-MA standard temperature

The standard temperature is 80 degrees C or less.

FY-MA accuracy

The accuracy is plus or minus 3 percent of each scale.

FY-MA contact rating

The contact is rated 5 A at 125 or 250 VAC.

FY-MA set point

The set point can be placed anywhere on the scale.

FY-MA options

Options include an externally variable contact and an IP67 waterproof type.

Switch records for the FY-MA

Record the set point, the line pressure and the date of each alarm test.

Choosing the right FY-MA connection

Choose the flange type for larger lines and the screw type for small lines.

Documents and quotation

The Kawaki instruction manual is attached; it is in Japanese. Seven Star LLC is an independent supplier in Muscat and can request a quotation when you send the model, bore, connection, fluid, temperature and flow range. Related items: Flow Indicators and Switches.