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FLOW
Product Data Sheet

DS1220

Platon Metal Tube VA Gas or Liquid
PLATON METAL TUBE VA FLOWMETER
TYPE GMT
GMT metal tube flowmeters are variable area meters
of totally welded stainless steel construction. Liquid
or Gas flowing up the tapered flowtube lifts the float
to an equalibrium position, dependent on flow rate,
and a magnetically coupled pointer indicates this
flow on an external scale. The large meter indication
is easily visible at a distance, with the pointer moving
over a 1500 scale. Each scale is produced specifically
for the fluid involved and process conditions
expected: several flow ranges are available for meters
of each standard line size. All gas flow meters are
supplied with an integral piston damper to smooth
out flow pulsations.
Installation is simple, in a vertical section of flow
line: meters can be supplied with EN, ANSI or other
standard flanges, or BSP or NPT screwed connections.
The robust construction with no glands or seals to
leak means the meters are suitable for high pressure
applications, or extremes of temperature.The standard
GMT is totally self contained and needs no external
power.
Alternative materials are available to special order for example Hastelloy or Monel wetted parts. For
lower cost, Brass or Stainless steel bodied meters `” 2” in size are available with screwed connections. The
indicator can be provided with one or two flow alarm
sensors, adjustable over the meter operating range.
Full electronic transmission and totalisation is also
available, using the “VAMPIRE” electronic module.

FEATURES
`” - 4” line sizes
No power required
Clearly visible meter
Scaled for process fluids
Easy installation - flanged or screwed
No glands or seals
Robust, simple construction
Pulsation damper on gas meter

PRINCIPLE OF OPERATION
The metering element consists of a precision machined
tapered tube and a float. The height to which the float
rises in taper is determined by the gap at which upward
flow force and float weight are balanced.
A permanent magnet encapsulated within the stainless
steel float drives the external magnetically coupled
pointer. Float movement is related to flow rate, and
the indicator scale is marked in the correct units of
flow for the process conditions.
The standard unit requires no electricial power.
Because the measuring element is a sharp edged disc,
the meter is relatively insensitive to viscosity changes
in the fluid, and to pipe bends in the external
pipework. The only moving part in the flow is the
float, which is retained in place by float guides at
either end of the meter.

Metal tube meters are ideal for arduous industrial
service as an alternative to large glass tube flowmeters.
They have particular advantages, where fluids are
opaque or staining, or to provide higher safety and
security for dangerous or toxic fluids.

DS1220

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