Serie FMFlussostato a paletta per impieghi gravosi
Costruito per resistere alle applicazioni industriali e minerarie più gravose. Flussostato a paletta robusto ma molto sensibile, con involucro in alluminio ricavato dal pieno e attacco al processo monoblocco in acciaio inox 316. Pressione nominale 400 bar, forzatura manuale integrata in tutti i modelli.

Caratteristiche
- Interruttore S.P.D.T. 5–500 V AC, 15 A (modello H)
- Disponibile il modello 'L' a bassa tensione con contatti dorati (FM-L)
- Attacco al processo monoblocco in acciaio inox 316
- Custodia in alluminio ricavato da pieno, estremamente robusta
- Comando manuale integrato
- Modelli da 3/4" e 1" disponibili con filettatura BSP o NPT
- Pressione nominale 400 bar (5800 psi)
- Trascinamento magnetico senza guarnizioni
- Versioni per gasolio e alta temperatura disponibili
- Custodia IP67 resistente agli agenti atmosferici
- Facile da sottoporre a manutenzione
La Serie FM usa lo stesso azionamento ad accoppiamento magnetico della Serie F — il movimento della paletta viene trasmesso all’interruttore ad alta sensibilità attraverso una parete piena di acciaio inox e alluminio, ottenendo un flussostato per alte pressioni senza guarnizioni, membrane, soffietti o altri punti di possibile guasto. Fornito di serie con attacco al processo monoblocco in acciaio inox 316 e involucro in alluminio interamente lavorato dal pieno. Disponibile con paletta in polipropilene rinforzato con fibra di vetro, oppure con paletta in lega nichel-rame per applicazioni con gasolio e ad alta temperatura. La paletta può essere tagliata e sagomata per tubazioni da 25 mm (1") o più grandi, e la forzatura manuale integrata attiva il flussostato con la semplice pressione di un pulsante, indipendentemente dal flusso. Adatto ad acqua di pozzo, acqua di mare e molte soluzioni chimiche.
Ulteriori informazioni
- Scheda tecnica Serie FM(versione in inglese)
- Istruzioni di installazione Serie FM-H(versione in inglese)
- Istruzioni di installazione Serie FM-L (bassa tensione)(versione in inglese)
- Download disegno 3D Serie FM (file .stl)
Ordini — modelli disponibili
Limiti di funzionamento
Dati elettrici
Dimensioni

Manual Override
All FM models include a red manual override button on the side of the housing, under the cable gland. Pressing it switches the flow switch on regardless of flow — useful for manually starting pumps in spite of an initial lack of flow, and for testing/commissioning of control circuits. After wiring, press it to test: the switch changes state as if liquid were pushing the paddle.
Flow Sensitivity & Paddle Trimming
Cut the paddle to suit the application — it must clear the pipe wall by at least 4 mm all round. Use a hacksaw or tin snips (heavy-duty tin snips for the FM-D metal paddle). As a guide: low flow — paddle just clears the bottom of the pipe; unknown flow — 3/4 of the way across the pipe; high flow — 1/4 to 1/2 of the way across the pipe. Spare paddles are available if too much is cut off. The flow rates required to actuate depend on turbulence, viscosity, and the exposed paddle area. Use the online Paddle Calculator to estimate activation flow and determine the right cut.
Sensitivity Adjustment
FM switches are supplied at maximum sensitivity (adjuster wound fully in). To decrease sensitivity, remove the red dust cap and wind the adjusting screw out (anticlockwise) with a wide flat screwdriver. The further out the screw, the more flow is needed to operate the switch. Refit the dust cap.
Dieseline / High-Temperature Variant
Order the -D suffix (e.g. FM-H-25B-D) for dieseline service or operation up to 100 °C. The polypropylene paddle is replaced with a Nickel Copper alloy paddle. Kelco products are not intended for use in hydrocarbons other than dieseline.
Mounting
The switch can go in suction or delivery pipework, horizontal or vertical. In vertical pipework the flow must be upward, not downward. Never install the switch on the underside of horizontal pipework. Where possible, mount the switch away from pumps, valves and bends — a fitting directly upstream makes the flow uneven and turbulent at the paddle, which can shift the switching point slightly or make the paddle flutter near the switching point; downstream fittings have little effect. Mount in a pipe tee, tapping saddle or weld-on socket, square to the flow so liquid hits the flat face of the paddle, with the arrow on the switch pointing in the direction of flow. Seal the thread with PTFE tape or thread sealant, leaving at least 4 mm of thread above the socket, and tighten with a spanner on the spanner flats only — never twist the switch body.
Electrical Installation
The FM Series is a mains voltage device — all electrical work must be carried out by a licensed electrician. Terminals are marked C (common), NO (normally open) and NC (normally closed); for a two-wire connection use C plus either NO or NC to suit the application. Connect the earth terminal inside the housing: the FM must be earthed when operated at mains voltage. After wiring, fully tighten the cable gland nut, check the lid gasket is in place and tighten the lid down. Without its lid the switch is not water, weather or insect proof and presents a shock hazard.
Hazardous Areas
The FM-H is not certified for use in hazardous areas and must not be installed in any area classified as hazardous under AS/NZS 60079.10 (Zone 0, 1, 2, 20, 21 or 22). The FM-L is simple apparatus under AS/NZS 60079.11 and may be used in a hazardous area only as part of an intrinsically safe circuit, connected through suitably certified associated apparatus. It is not Ex certified in its own right. The associated apparatus must not exceed Uo ≤ 30 V, Io ≤ 100 mA. The full conditions of use are given in the installation sheet.
FM-L — Inductive and Capacitive Loads NOT Suitable
The FM-L is not suitable for inductive or capacitive loads such as contactors and relays. Loads above the rating will damage the switch.
Replacing the Paddle
The paddle and its associated pivot bearings are replaceable items. Spare paddles can be obtained from your supplier — please quote the part number of the flow switch when ordering. Replacement paddles are supplied with new bearing shells and a large retaining O-ring. On FM-D models the nickel copper alloy paddle, main arm and bronze pivot bearing are also replaceable; never undo or remove the sealed hexagonal cap at the top of the main arm, which houses the magnet.
Materials & Chemical Compatibility
All FM models have a one-piece 316 stainless steel process connection and a billet aluminium housing. The standard FM has a glass-fibre-reinforced polypropylene paddle for water use; the FM-D has a nickel copper alloy paddle. Suitable for use in bore water, sea water and many chemical solutions. Check that the switch materials suit the liquid being monitored.
Approved Standards
The 'H' and 'L' microswitches used in the FM Series are approved to UL1054 (File E41515), CSA C22.2 No.55 (File LR21642) and EN61058-1, and are CE marked.
Manutenibilità
Interamente riparabile sul campo. La paletta e i suoi cuscinetti del perno sono parti sostituibili (sul FM-D: la paletta in lega nichel-rame, il braccio principale e il cuscinetto del perno in bronzo). L’involucro elettrico è un gruppo separato che si blocca sulla parte bagnata con una sola vite accessibile dall’esterno — i moduli si sostituiscono senza toccare le tubazioni. Palette, guarnizioni e interruttori di ricambio sono disponibili presso Kelco Engineering o il Suo distributore.

