Frequently Asked Questions | JT Systems

CROFT JT System on green skid

Croft Production Systems offers skid-mounted Joule Thomson Systems that simultaneously reduces the water dew point of gas, recovers valuable hydrocarbon liquids, and lowers the BTU (British Thermal Unit) of the gas stream to sales contract specifications or levels suited for high-speed engines.

These pre-assembled systems are delivered ready to be installed on location and are contained on a single skid. This space-saving system is installed by experienced CROFT personnel, who will ensure everything is running smoothly and continue to monitor the JT System monthly.

What is The Turndown of CROFTs JT Units?

The turndown of CROFT JT Units depends on the trim size in the motor valve of the JT system. You can get the trim turndown by the manufacturer of contact CROFT to run through the simulation. An indicator of incorrect size is when the pressure differential starts to decrease, and you are not achieving the pressure drop required.

How Cold Does a CROFT JT System Get?

 It depends on the design of the individual JT system, but the rule of thumb is for every pressure drop, you get a 10-degree temperature drop. When you install better heat exchangers and better insulated thermal barriers, you may achieve better ratios like 15 degrees for every 100 pressure drop. CROFT can operate our JTs around -20 degrees, but it depends upon the system’s goal, either BTU reduction or NGL recovery, which will dictate the required temperatures.

What Volumes of Gas can CROFT JT Systems Handle?

Croft Production Systems offers skid-mounted Joule Thomson Systems designed to handle gas streams between 1 to 10 MMcfd. While we can build a custom application for whatever the client parameters are, our standard package skid units come into two-million, five-million, and 10-million cubic-feet-a-day packages.

How DO Crofts JT Systems work?

CROFT skid-mounted JT System

Gas enters the Joule Thomson System and travels through heat exchangers that pre-cool the gas. The gas then passes through the Joule Thomson valve, taking a pressure drop and cooling further. Liquid fallout after the Joule Thomson valve is collected in the cold separator and sent to storage tanks. The cold gas travels back through the heat exchanger and exits the Joule Thomson System. Check out our JT Video for a step-by-step explanation.


Learn more about CROFT Joule Thomson Systems or Request a Quote.

Posted on Sep 2, 2020 by Chris Smithson

Chief Technology Officer

Mr. Smithson graduated from the University of Houston with a Bachelor of Science in Mechanical Engineering Technology. He joined CROFT’s Engineering Team in 2011, with a vision to improve CROFT products and designs for production equipment. During Mr. Smithson's tenure with CROFT, he was promoted several times, and currently holds the role of Chief Technology Officer. Under his leadership, the CROFT Team has launched multiple new product lines; CROFT’s Chemical Injection System (for which he personally received a patent), Fuel-gas Conditioning System, and Ambient Cooling System, as well as improving the designs of the Gas Sweetening System and Joule Thomson System product lines. Mr. Smithson’s expertise and leadership include consulting on multiple oil and gas projects around the world, plus CROFT’s technology advancements by implementing the latest 3D CAD design/analysis software, product data management, along with process simulation software for Chemical and Hydrocarbon processes. Ultimately, Mr. Smithson’s main focus is to continue to improve CROFT’s products and designs to meet industry demand.

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