KROHNE Summit 8800 Vol 2 - Manual (Page 36)

36 www.krohne.com 08/2013 - MA SUMMIT 8800 Vol2 R02 en
SUMMIT 8800 METERING PRINCIPLES 03
3 .10 .1 Unidirectional ball prover
An inlet and outlet are connected to the pipework. A unidirectional prover only has flow in one
direction and the volume is based on the switching of the first detector switch followed by the
second with a passing sphere (displacer) used as a trigger.
Figure 12 Uni-directional prover
3 .10 .2 Bi-directional pipe prover
In a bi-directional prover the flow can be reversed With the use of a four way diverter valve. The
prove cycle is performed under operating stabilised conditions to maximize the accuracy.
PT TT TT PT
XS XS
Figure 13 Bi-directional prover
Key
PT – Pressure transmitter in/outlet
TT – Temperature transmitter in/outlet
XS – Detector switches