Addendum to SUPERtrol II Manual For Manifold Controller
Manifold Controller using the ST2
General Description-
The piping layout for a ow measurement manifold is shown in gure-1. Such owmeter manifolds are used to increase
the ow measurement turn down range beyond that which can be satised by a single owmeter.
The ow measurement manifold consists of:
High ow range owmeter
Low ow range owmeter
Bypass valve
Flow Measurement Instrument/Controller
Interconnecting piping
Ancillary temperature and pressure measurement devices (as needed)
The principle of operation is that the ow is always measured by the larger owmeter. If the larger owmeter indicates a
ow measurement below its measurement range, a bypass valve is closed diverting all the uid ow through the smaller
ow meter where the measurement is made.
In the case where the bypass valve is open, most of the ow is diverted around the smaller owmeter. The portion of the
uid passing through the owmeter may cause the meter to coast, but it will not be overranged.
Operation of the Flow Measurement Instrument/Controller using ST2-
A owmeter manifold controller is a special ow instrument intended to accept inputs from two owmeters, one larger and
one smaller, and which also controls the bypass valve. The instrument setup contains the calibration information for both
owmeters as well as the manifold ow rate switch setpoint and hysteresis.
The instrument operation may be summarized as follows:
1. Measure the ow rate signal from the high range owmeter
2. Decides if the owrate is below the user specied low ow rate for the high range owmeter:
If yes, close the bypass valve
If no, open the bypass valve
3. If the bypass valve is open display owrate and totalization based on the high range owmeter
If the bypass valve is closed, display owrate and total based on the low range owmeter
4. Analog Output, Relays, Pulse Output, etc... is based on which owmeter is active at the time.
This special version of the ST2 has two analog, ow input channels.
Valve Specications-
The valve should be a normally open energize to close valve of the same line size as the larger owmeter.
To be effective as a bypass around the smaller owmeter the valve should present a minimal pressure drop at the maxi-
mum owrate. Full port valves perform best.
User Wiring-
1. Wire the analog input for the high range meter to terminal 2
2. Wire the analog input for the low range owmeter to terminal 3
3. Wire the normally open control valve to Relay 1 terminals NO and COM
99607 03/03/10
