Piping System Brain Teaser #3: System Troubleshooting Part 1
A key aspect of troubleshooting a problem in a piping system is knowing what the "normal" operating conditions are for the flow rates, pressures, valve positions, and other measured values in the system. If you don't know what is "normal", it will be hard to identify an "abnormal" operating condition.
The end result of troubleshooting is to determine the root cause of the problem and fix it. Many times troubleshooting becomes an exercise in how many components can be torn apart or replaced in hopes of finding that root cause. But if you understand the operation of each component in the system and how the total system operates, troubleshooting becomes a methodical and logical analysis of the values of process measurements throughout the system.
So let's test your troubleshooting skills using PIPE-FLO models (no heavy rigging, turning wrenches, or wiping sweat from the brow required). Given the normal operating conditions shown in Figure 1, determine the root cause of the problems indicated by the process measurements in Figures 2 and 3. Potential Root Causes are listed below the Figure 3. We'll have two more troubleshooting examples next month!
Figure 1. Normal operating conditions
Figure 2. Problem 1: A problem in the system is causing a reduction in the entire plant production rate.
Figure 3. Problem 2: Plant expansion is being considered and requires this system to deliver 1200 gpm to the Product Tank, but an operation test showed the system could only deliver a maximum of 1015 gpm
|Problem 1: _______________||Root Cause A: Excessive Control Valve seat or disc wear|
|Problem 2: _______________||Root Cause B: Supply Tank Level Transmitter incorrect|
|Root Cause C: Plugged Heat Exchanger|
|Root Cause D: Supply Pump damaged or worn|
SOLUTION: 1-C, 2-D