6
2
O
VERVIEW
2.1
I
NTRODUCTION
Sentinel 2 is a system that is used to control the outlet pressure of a pressure reducing
valve (PRV) within a clean-water supply pipe network. This section gives an overview of
Sentinel 2, the equipment that is required to use it, and other (optional) system
elements.
The system is designed to control pressure reducing valves that are designed and
manufactured by 3
rd
party suppliers. Only general details of PRV valve construction are
included in this manual, and any images are for illustration purposes only.
Pressure control can be:
•
2-point control:
i.e. Automatic switching between two pre-set pressure levels (High and Low).
The Sentinel 2 product is ideal for this situation.
•
Continuous control:
i.e. Incremental adjustment of pressure, between a maximum and minimum;
The Pegasus 2 product is ideal for this situation.
(Refer to the Pegasus 2 manual for further details)
Sentinel 2 switches the PRV output pressure to either a High or Low setting based on a
pre-determined pressure profile.
The profile can be based on:
•
The time of day, or
•
The flow rate (demand) of water, or
•
Both of the above.
The pressure profiles are defined by settings or tables within the unit. Tables can be
entered manually during installation. Sentinel 2 can also communicate with a central
server that stores its measurement data. The server can be used for remotely analysing
the effectiveness of the pressure control and (if required) remotely update
the unit’s
settings. (This is achieved via PressView web software).
The system also offers a fail-safe mode, where it can operate the PRV at a fixed outlet
pressure when certain fault conditions occur (e.g. detection of a sensor failure).
Sentinel 2 includes a built-in data logger.
The Sentinel 2 system typically consists of the following parts:
•
A Control Box unit.
•
A Hydroswitch unit.
•
A HWM mechanical actuator.
•
An accessory kit for plumbing-in the Sentinel 2 system to work with the PRV.
(HWM can supply standard kits containing coloured plastic tubing, a 3-way
manual valve, quick-connect fittings).
•
Hanging bracket.