Why are seal pots used on flow installations?

Field Instrumentation Flow Measurement
1

Why are seal pots used on flow installations?

image

2

Seal pots are essential components in various industrial processes, particularly in applications involving high-density or corrosive media. Here’s why they are used:

  1. Protection of Differential Pressure Measuring Instruments:

    • Seal pots serve as a protective barrier between the process fluid and differential pressure measuring instruments (such as differential pressure transmitters).
    • When the process fluid is aggressive, dense, or corrosive, it can damage or clog the delicate sensing elements of these instruments.
    • By using a seal pot, the sensitive components remain isolated from direct contact with the process fluid.

  2. Barrier Fluid Layer Formation:

    • The seal pot contains an unmixable sealing liquid (often referred to as barrier fluid).
    • Due to the difference in density between the barrier fluid and the process fluid, a sealing layer forms at the interface.
    • This layer acts as a buffer, preventing the process fluid from directly affecting the instrument.

  3. Safety and Environmental Protection:

    • In hazardous environments where toxic or reactive substances are present, seal pots play a critical role.
    • They prevent leaks of hazardous materials into the atmosphere.
    • By maintaining a barrier, seal pots enhance safety for personnel and protect the environment.

  4. Cooling and Lubrication:

    • Some seal pots include cooling coils to manage the temperature of the barrier fluid.
    • Proper cooling ensures that the mechanical seals and other components remain within their operational temperature limits.
    • Lubrication of mechanical seals is also facilitated by the barrier fluid.

  5. Monitoring and Maintenance:

    • Seal pots often have level switches or transmitters to monitor the barrier fluid level.
    • Regular checks ensure that the barrier fluid remains at the correct level.
    • Maintenance procedures involve refilling the seal pot as needed.

Remember that seal pots are commonly used in conjunction with mechanical seals, especially in pumps. They contribute to the overall reliability, safety, and longevity of the instrumentation system