🔍 Key Concepts

• Trace the piping connected to V4 carefully and note whether it is on the oil, water, or steam side of the system. • Look at how opening V4 would change the flow through the preheater and what effect that has on oil pressure and temperature at the outlet. • Compare the effect of that flow change with the specific alarm options listed on the EPC Alarm Indications Program Unit panel.

💭 Think About

• When V4 vibrates open, does more oil go through the heater, bypass the heater, or return somewhere else? How would that change the temperature after the preheater? • Would opening V4 tend to increase or decrease pressure at the oil outlet line leading to the separator? How does that relate to the available alarm choices? • Which of the listed alarms (low outlet pressure, low temperature after preheater, high temperature after preheater, no discharge) best matches the hydraulic and thermal effect of opening this regulating valve?

✅ Before You Answer

• Verify on the diagram whether V4 is upstream or downstream of the preheater and whether it connects to a bypass/return line. • Confirm which sensor locations on the illustration correspond to temperature after preheater and pressure at oil outlet. • Check that the chosen alarm condition is one that would plausibly be triggered without completely stopping discharge, since the valve is only vibrating open, not fully shutting the line.