Description:

METAL TUBE Variable Area Flow Meter

The Type PMTR variable area flow meter is designed for measurement of small and large flow rate of fluids that are transparent as well as opaque. The conical metal metering tube has a guiding float. The flow is indicated by a needle and can be read from standard scale on the indicator box. Models can be fitted with switches for low & high flows. Models can be also be fitted with electrical signal output 4 to 20mA with hart communication.

Features:

- Direct Flow Indication.

- Wide selection of measuring ranges.

- High accuracy even at high flow rates.

- Low pressure loss.

- Non – Powered local indication.

- Measuring section of rugged all – metal construction.

- Tapered Measuring tube.

- Resistance to extreme chemical, mechanical & thermal loss.

- Option Built – in valve.

Applications:

The type PMTR is an ideal for any application that requires flow measuring of either gas or liquid.

-Fine metering and gas chromatography

-For on – line flow measurement

-For very High pressure fluid system monitoring.

-For very High Temperature fluid system monitoring.

Operations:

PRINCIPLE OF OPERATION:

The type PMTR is made of stainless steel continuously tapered tube. The outlet will be of larger diameter than inlet and the plummet / float is designed so that it occupies almost all the total tube area when it is at the small end of the tube. As the fluid is allowed into the tube, the float will be pushed up until the differential pressure across the float results in a force under it that is just equal to the effective weight of the float.

The effective weight is equal to the weight of the float minus the buoyant force of the fluid being measured. For a given fluid and a particular plummet, the effective weight is constant. Since the effective weight is constant, the differential pressure across the plummet is constant. As the flow rate changes, the annular area must change to accommodate the various flow rates. Since variable in area, the position of the float within the length of the tube can be used as a measure of the flow for a given tube. Hence the float position can be used to determine flow. The float is coupled with the indicator needle by magnet thus a non – contact transfer of the flow indication takes place.