Armfield PCT40 - Exercise D - Proportional Pressure Input with On;Off Controller Using Normally Closed Solenoid Valve

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Exercise D - Proportional pressure input with on/off
controller using Normally Closed solenoid valve
Objective
To control the level in the process vessel using an on/off controller connected to a
pressure sensor, with a Normally Closed solenoid valve (SOL1) controlling inflow to
the vessel.
Equipment Required
PCT40 bench with large process vessel, inner cylinder and supplied flexible tubing.
Overview
The level control method in this exercise uses a pressure sensor with an output
proportional to the pressure exerted on the sensor, calibrated in millimetres of water.
This sensor is normally used to indicate the level of fluid within the large process
vessel, but for this exercise the output is also used to control a flow control valve via
the computer, in this instance an on/off solenoid valve.
Equipment set up
Ensure that the apparatus has been set up according to the assembly sheet (see
also Appendix A in this manual). Ensure that the inlet connector for the apparatus (on
the right of the plinth behind the pressure regulator) is connected to a suitable mains
water supply. Check that the central cylinder is securely in position inside large
process vessel. Using a suitable length of tubing, connect the self-sealing connection
socket on the base of the large process vessel to the quick release connection on the
valve SOL1 at the front right of the plinth.
The drain valve at the end of the plinth should be directed to a drain and left open.
Solenoid valves 2 and 3 should be connected to a suitable drain using the tubing
supplied. The drain valve in the base of the large process vessel should also be
connected directly to drain using flexible tubing.
Connect the apparatus to a suitable PC on which the software has been installed
using the pale grey USB cable supplied. The flat connector on the cable connects to
the PC, usually via a socket at the back. The other end connects to the socket on the
orange panel on the front of the plinth. Check that the PC is working and switched
on.
Procedure
Switch on mains power to the console. The apparatus should not be left unattended
once in operation, and manual operation of the inlet pressure regulator and drain
valve should be used to control the fluid level if the vessel volume reaches the
overflow pipe, or the drainage channel in the plinth becomes full of water.
Run the PCT40 software and select Section 1: Level Control (inflow). Select the
icon to view the mimic diagram screen.