Model S single tube flow meters are similar to P meters in design,
employing the same interchangeable flow tubes, valves, and accessories.
Likewise they may be panel or bench mounted.
The primary advantage of the S meter is convenience in applications,
where frequent changing of tubes in meter cases is desired. An example
is when several flow tubes are used in conjunction with a single meter
case, or when because of the nature of the fluid, periodic cleaning
necessitates disassembly.
Aalborg’s exclusive TUBELOK™ design
facilitates simple installation and replacement of tubes in mounting
cases. As a result of the "non-rotating” adapter feature, glass flow
tubes are prevented from turning during the tightening phase of the
assembly procedure.
Flow tubes for these meters are available with two types of scales, suitable for different types of applications
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.
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 |
