Solution:

​

The system shown above consists of a heat exchanger, at the top, in the Loop 301 there is a temperature valve, which is connected by pneumatic signal a temperature transmitter (TT) with a transducer (I/P) which in turn is Connected by means of electrical signal to an operator accessible temperature indicator controller (TIC) to open or close the steam step.  A temperature transmitter (TT) connected with a capillary tube to the heat exchanger is connected to the same form by electrical signal and thus can census the temperature within it.      On the left-hand side, in Loop 101, the process fluid enters the system, which can be cooling water. A temperature valve (TV) of the type "opening by Fault" (FO) is found as a safety system to allow the fluid to pass in case the temperature exceeds the indications. To this valve is connected by means of pneumatic signal a controller of temperature accessible to the operator (TRC) to which by means of electric signal is connected by interlocking a very high temperature alarm (LAHH) which will indicate when the temperature is Find too high and then a switch (TS) and a low temperature alarm (TAL) are connected.

A temperature transmitter (TT) that is connected to the output of the system process fluid and which indicates that the temperature at the outlet is adequate is connected by electrical signal to the temperature recorder controller, otherwise it indicates to the Recorder controller to operate the temperature valve.  The transmitter is protected by a thermo-well (TW) to avoid damage due to high temperatures.      At the bottom, in loop 203, is connected to the heat exchanger a level transmitter (LT) that reported the level of fluid within, it is connected by electrical signal to an operator accessible level indicator (LIC) with Transducer and this one in turn connected by means of pneumatic signal to a safety valve (LV) of the type "close by Fault" (FC) which will be closed when the transmitter sends the signal to the indicator controller that the fluid level inside the heat exchanger is not sufficient, otherwise it will open and allow the surplus fluid to pass through.