General Description - Sentry Sample II Low Pressure Installation, Operation & Maintenance Manual

General Description

Flow control of water and steam sampling is important to help assure the quality of
the samples and repeatability of the analytical results. Constant flow in the sample line
minimizes the chance of modifying the chemistry of the samples of high purity water
through entrapment and/or release of soluble species from deposits in the system.
Sample inlet temperature and flow are easily controlled under constant conditions.
However, since sample pressures typically fluctuate, maintaining a representative sample
can be difficult and labor intensive. The traditional manual sample conditioning system
can require constant adjustment during startup or as plant conditions change.
Sample Sentry II is designed to meet requirements for representative sampling by
maintaining a constant flow rate with varying inlet conditions. Automated flow control is
achieved by continuously monitoring the sample flow rate and controlling a motorized
pressure reduction valve (PRV). An actuated ball valve and solenoid valve controls the
flow path, allowing for automatic startup and shutdown of the system. Flow control is also
available in a manual mode, allowing the operator to control the system with a keypad
on the controller. Sensors allow the controller to monitor temperature, pressure, and flow
and shutdown the system when an alarm occurs. Programmable options in the controller
allow Sample Sentry II to conform to a variety of sampling applications.
6 Sentry Equipment Corp