Why heat exchanger leak

First of all, the newly installed plate heat exchanger leaked during debugging. This is usually caused by the loosening of the clamping bolts, because the plate heat exchanger has been bumped for a long time during transportation. If the clamping bolts are pre-tightened unevenly , It will cause the problem of loosening, which will lead to the change of the clamping size and leakage.

Secondly, leakage occurs after a long time of use, which is generally caused by aging of the rubber strip or plate corrosion. It is especially common for plate heat exchangers under high-temperature steam conditions. The sealing of the rubber strip is limited by the material of the rubber strip. Any marked increase in the conductivity of the condensate indicates that leakage is present, and the condensate should be sent to drain.

As shown in the simplified diagram below, the conductivity instrument can be utilized to directly control the dumping of contaminated condensate. A single point conductivity analyzer EXA SC can be located downstream of the heat exchanger, and utilize a high alarm relay to actuate the valve. Another option is to use a dual input conductivity analyzer EXA DC with one sensor upstream of the heat exchanger and one downstream.

The built-in deviation calculation of the analyzer can be used to alarm, or actuate a valve, when the downstream conductivity deviates significantly from the upstream conductivity. This method compensates for any variance in the condensate conductivity. Measurement and control of Heat Exchanger Leakage can help prevent costly maintenance, repair and downtime.

The simple, essentially maintenance-free measurement of condensate conductivity will give the operator information necessary or provide automatic control to prevent severe damage to the boiler should a breakthrough of the heat exchanger occur. Yokogawa has been serving the bulk chemical market globally and is the recognized leader in this market. With products, solutions, and industry expertise, Yokogawa understands your market and production needs and will work with you to provide a reliable, and cost effective solution through the lifecycle of your plant.

Chemical plants rely on continuous and batch production processes, each posing different requirements for a control system. A continuous process calls for a robust and stable control system that will not fail and cause the shutdown of a production line, whereas the emphasis with a batch process is on having a control system that allows great flexibility in making adjustments to formulas, procedures, and the like. The build up of corrosion products and stress can cause cracking and fatigue in the material of the system.

To lower the likelihood of stress corrosion cracking, the heat exchanger should not have crevices where media can become stagnant allowing materials to accumulate. A heat transfer unit is designed for a maximum pressure. When that maximum is exceeded holes and cracks will begin to form allowing media to leak from the unit. Think about vehicles driving across a bridge, year after year pressure is applied to the bridge supports causing normal wear and tear on the structure. However, if the bridge is not properly braced, then the supports will become stressed.

The bridge will not be able to support the load traveling across which and may fail. This is similar to a heat transfer unit, but instead of vehicles traveling across a bridge, there is media flowing through the system.

Heat transfer leaks should not be taken lightly since the product within your system can become contaminated no matter what caused the leak. This problem occurs because the flange of the heat exchange unit uses a cushion made of oil-resistant asbestos rubber sheet.

The sealing of the floating head cover and the floating head tube plate of the heat exchange unit is that two hooks are clamped on the back of the tube plate to form a hook flange, which is connected by bolts. The hook flange is integrally processed and cut into two pieces.

This will lead to a reduction in the amount of compression of the flange on the cushion and eventually puncture.