Série FMChave de fluxo de palheta para serviço pesado
Construída robusta para as aplicações industriais e de mineração mais exigentes. Chave de palheta resistente e altamente sensível, com carcaça de alumínio forjado e conexão de processo em aço inoxidável 316 de peça única. Pressão nominal de 400 bar, override manual integrado em todos os modelos.

Recursos
- Chave S.P.D.T. 5–500 V CA, 15 A (modelo H)
- Modelo «L» de baixa tensão com contatos de ouro disponível (FM-L)
- Conexão de processo em aço inoxidável 316 de peça única
- Carcaça super resistente em alumínio forjado
- Override manual integrado
- Modelos 3/4" e 1" disponíveis com rosca BSP ou NPT
- Pressão nominal 400 bar (5800 psi)
- Acionamento magnético sem vedações
- Versões para diesel e alta temperatura disponíveis
- Carcaça à prova de intempéries IP67
- Fácil manutenção
A série FM usa o mesmo acionamento por acoplamento magnético da série F — o movimento da palheta é acoplado à chave de alta complacência através de uma parede sólida de aço inoxidável e alumínio, resultando em uma chave de alta pressão sem vedações, diafragmas, foles ou outros pontos de falha potencial. Fornecida de série com conexão de processo em aço inoxidável 316 de peça única e carcaça de alumínio forjado totalmente usinada. Disponível com palheta de polipropileno reforçado com fibra de vidro ou palheta em liga de níquel-cobre para aplicações com diesel e alta temperatura. A palheta pode ser cortada e moldada para tubulações de 25 mm (1") ou maiores, e o override manual integrado liga a chave de fluxo ao pressionar um botão, independentemente do fluxo. Adequada para uso em água de poço, água do mar e muitas soluções químicas.
Pedido — Modelos disponíveis
Limites de operação
Dados elétricos
Dimensões

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.
Manutenção
Totalmente sujeito a manutenção em campo. A palheta e seus mancais de pivô são itens substituíveis (no FM-D, a palheta em liga de níquel-cobre, o braço principal e o mancal de pivô de bronze). A carcaça elétrica é um conjunto separado travado na parte úmida por um único parafuso acessível externamente — trocar módulos sem desmontar a tubulação. Palhetas, vedações e chaves de reposição disponíveis na Kelco Engineering ou no seu distribuidor.

