TEG Cleanout Utilizing Mobile PDS

Do you dread the anticipation of having to clean out your TEG? Having to shut down your operation for a few weeks? Here at CROFT we offer a mobile Passive Dehydration System.

It is a quick, easy and a temporary way to bypass a TEG and continue to dehydrate the gas while your TEG is shut down getting serviced/cleaned out.  

Our PDS is a very simple system. It has no moving parts, no powered components, no fires, no boilers, no permits required, and has a modular system structure that has limited emissions. Our PDS is a non-regenerative system, which means it uses a deliquescent adsorbent to dry the gas. The desiccant we use in our system is called enviroDRI, which is a hydroscopic compound that adsorbs water vapor.

Passive Dehydration System StepsPDS  (1)

Step 1: The PDS accepts wet gas through the Gas In Valve

Step 2: Water vapor is removed as gas moves through the vessel

Step 3: Gas Enters the sales line per pipeline specifications

Step 4: Time to refill 



The Recommended TEG Cleanout Steps:

The steps below do not comprise of all the actions in a TEG cleanout, and do not necessarily all have to be completed, but are suggested. As you can see the list of items will take a while to complete. We recommend installing a PDS unit while cleanout is being done. This process is typically smoother and less installation will be involved.

  1. Drain system of existing fluids.
  2. Flush unit until clean and drain.
  3. Remove, clean, and inspect burner flare arrestor assembly.
  4. Remove burner and clean orifice and burner assembly. Replace pilot assembly with BMS pilot.
  5. Remove and clean packing from still column. Replace if necessary.
  6. Make new still column and smoke stack gasket.
  7. Disassemble piping and inspect for corrosion and buildup. Clean if necessary.
  8. Replace and missing glycol piping.
  9. Inspect and hydrotest
    • All ASME code pressure vessels
    • Glycol/glycol heat exchanger
    • Still Column Coil
  10. Open filters, inspect and clean.  Replace elements.
  11. Replace Kimray pump with Kimray tested pumps.
  12. Replace all valves 1” or less if not easily moveable.
  13. Test operation and integrity of all larger valves. Replace seals of any union valves.
  14. Replace entire fuel gas and instrumentation system. New piping, valves, regulators, gauges, etc. Pneumatic instrumentation system will be piped for outside air supply.
  15. Install Platinum BMS system. Solar powered with battery backup, Pilot ignition system.
  16. Wire all electronic instrumentation into the BMS or on-skid junction box. Test functionality.
  17. Replace insulation on slash tank, redo caulk on reboiler.
  18. Replace all control valves and level controllers with new.
  19. Replace sight-glasses glass tubes and isolation valves.
  20. Tube all pneumatic controllers into instrumentation system. Test for functionality.
  21. Replace all PSV’s with new.
  22. Remove Stack Arrestor.

Again, these steps take time. Installing a PDS temporarily during a cleanout can save money and time without loss of production. The picture below shows a quick temporary installation of a PDS dehydrator while the client’s TEG is being cleaned out and preventative maintenance is to be completed. 





If you are interested in a TEG, PDS or a TEG Cleanout option, CROFT can help with all gas processing solutions. Request a quote.