model P single flow tube meters

model P single flow tube rotameter for low flow rate measurement

Design Features

rib-guided or fluted metering tubes facilitate stable and accurate readings
magnifier lens in front shield to enhance reading resolution
interchangeability of flowtubes and floats
ease of installation and exchange of flow tubes
"non-rotating" adapter feature - glass flow tubes are prevented from turning during the tightening phase of the assembly procedure
OPTIGRAD™ scales minimize parallax and eye fatigue
chemical compatibility
simple means of panel mounting

Designed for low flowrates, the model P flowmeter is a precision instrument embodying the inherent simplicity, versatility and economy of the classical variable area meter. It is particularly suitable for metering carrier gases in chromatography, indicating and controlling gases in manufacturing processes, liquid and gas measurement in laboratories, pilot plants, flow and level indicating, etc. 150 mm Meter with CV™ Valve. Shipped completely assembled, flow meters include standard mounting fittings in a choice of materials, side plates, thick protective magnifying front shield and back plate, optional built-in control valve, and flow tubes selected from the Flow Capacities tables.

Flow tubes for these meters are available with two types of scales, suitable for different types of applications

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DIRECT READING SCALES

Direct reading scales are indicating flow rates of liquids and gases,in engineering units such as [mL/min], standard cubic feet per hour [scfh] etc. Such scales are designed exclusively for a specific gas or liquid at a given set of pressure and temperature parameters, and are valid for the associated units of flow only. The convenience of direct reading scale designs should be weighed against the resultant limitations of applicability. Generally, direct reading scales are most suited to OEM applications.

UNIVERSAL MILLIMETER (CORRELATED) SCALES

Millimeter scales indicate the vertical position of the spherical float within the metering tube as the flow increases or decreases.
It is necessary to use flow tables or graphs supplied, to correlate float referenced readings with actual volumetric flow rates.
The advantage of Universal type scales is the ability to utilize the use of a given flow meter for a great number of different fluids at diverse pressure and temperature conditions, generally preferred in applications in laboratories, etc.

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BUILT-IN VALVES

Meters are available with built-in needle valves (CV™), high precision metering valves (MFV™) with “non-rising stems”, or with no valves. The higher cost of MFV™ valves is justified whenever high sensitivity control and resolution are desirable particularly in conjunction with metering tubes of very low flowrates.

Generally, for gas metering it is recommended that valves are positioned at inlets (bottom) for liquids valves may be positioned either at inlets or outlets (top). For vacuum services, valves must be mounted at outlets. If unspecified at the time of ordering, meters will be shipped with valves mounted at the inlets.

SPECIFICATIONS

STANDARD ACCURACY ±2% FS (mm scales - except 032/042 flow tubes); ±5% FS (direct reading scales and 032/042 flow tubes)

CALIBRATED ACCURACY ±1% FS

REPEATABILITY ±0.25% FS

USEFUL FLOW RANGE 10:1 minimum with one float and better than 20:1 with combination of two floats installed in meters

MAXIMUM OPERATING PRESSURE 200 psig (13.8 bars)

MAXIMUM OPERATING TEMPERATURE 250°F (121°C)

MATERIALS OF CONSTRUCTION

FLOW TUBES heavy walled borosilicate glass

FLOATS glass, sapphire, 316 stainless steel, carboloy and tantalum

SIDE PANELS aluminum, black anodized

FRONT SHIELD Lexan® with longitudinal magnifier lens for enhanced reading resolution

BACK PLATE 1/8 inch thick white acrylics

O-RING and PACKING Buna-n o-rings standard in aluminum and brass models; Viton® o-rings standard in stainless steel models; optional Viton®, PTFE/Kalrez®, EPR

CONNECTIONS 1/8 inch NPT female inlet and outlet connections; optional 1/4 inch FNPT, hose and compression fittings are available