Knock-Out Pots

Gas and Liquid Separation

TM Filtration's multi-phase separators and knock-out pots are used in a wide range of applications. These vessels will remove large amounts of unwanted liquids from the air/gas stream.

Multi-Phase Separation via:

  • Impingement
  • Vane Pack
  • De-Mister Pad
  • Cyclonic

Application Specific Housing Configurations

  • Vertical Housing
  • Horizontal Housing
  • Offset Nozzles
  • In-line Nozzles


  • Removal of viscous liquids
  • Recovery of product in some chemical applications
  • Prevent carryover of corrosives or unwanted materials.
  • Vacuum pump protection
  • Compressor protection
  • Upstream or downstream of gas conditioning skids

Design Information:

  • Designed for both pressure and vacuum applications
  • Minimal Pressure drop (< 1.0 psid)
  • High Efficiency: 99.8% > 10 micron removal of liquids.
  • Designed and manufactured to comply with:
    • ASME Section VIII Div. 1 (‘U' Stamp optional)
    • API Specification 12J Specification for Oil & Gas Separators
    • ASME B16.5 Flanges
    • ASME B36.10 Carbon Steel PIPE
    • ASME B36.19 Stainless Steel Pipe

TM Filtration Design Principles

Our multi-phase separators are designed to force the contaminated flow through a series of mechanical obstacles that are specifically sized to efficiently remove liquids and particulates based on pressures, temperatures, and gas composition.

We evaluate each application and run a series of calculations based on volumetric separation (slowing gas velocities) and we then run it through our "Pulse" program which then sizes the vessel for the least amount of pressure drop. Finally, we run our pressure vessel design program to evaluate wall thickness and required testing per ASME code requirements.

The design of our vessels begins with the geometry of the housing with regard to the gas inlet and the gas outlet. The inlet is low in the vessel where the cleaning starts to take place. The outlet is high, the last place the gas is exposed to, and it's the cleanest part of the vessel. In some cases, our customers require an "in-line" or horizontal construction, where we would then configure the internals accordingly to get the same result.

Inlet Impingement

Heavy liquid and particulate removal begins by being centrifugally spun at the inlet by use of an impingement plate designed to force the gas flow to the walls of the vessel removing heavy particles and droplets by use of inertia and gravity.

Details: 304 Stainless construction
  Liquid slug and large particulate removal


The gas flows through the vane pack, changes direction again and again and then through a series of parallel plates formed into a labyrinth having “hooks” which constantly face oncoming gas, forcing the particles to impinge and become trapped in the vertical troughs and drain to the bottom of the vessel.

Details: 304 Stainless construction
  <= 10 micron @ 98% efficiency

Mesh (De-mister Pad)

The remaining particles travel upward and through the mesh pad where the fine droplets of entrained liquids impinge on the extensive surface of the pad and they coalesce into large droplets. When they become of sufficient size, they break away from the wire mesh and drop to the bottom of the vessel.

Details: 304 Stainless construction
  Liquid slug and large particulate removal

Separation Configurations