NGL Truck Offloading Compression System

A recent project was an NGL Truck Unloading compressor skid designed by S&S Technical for installation at a fractionation facility in Ohio. The client was looking for an automated compression skid that would be designed to offload transport trailers delivering a Propane/ Butane mix (“Transmix”) as well as a heavier hydrocarbon mixture (“Light Condensate”). The system’s offload rate is controlled by a LACT skid that utilizes a VFD to control the compressor speed. The system is sized to offload the Transmix at a maximum rate of 400 gpm and the Condensate at a maximum rate of 300 gpm.

How To Design An NGL Truck Unloading Skid

For this application, a Corken T891 double-acting, oil-free industrial gas compressor was selected. The compressor included a purge system to eliminate fugitive emissions that can result from worn or damaged seals. Due to the gas compositions, we included an oversized suction scrubber with two ultrasonic level switches to prevent liquid “slugging”.

The NGL compressor skid also includes pressure and temperature switches and transmitters for automated start/stop function as well as equipment safety. All of the piping was welded and tested in accordance with ASME B31.3 standards and all of the instrumentation was selected and installed to meet Class 1, Div. 2 area classification requirements.

How Did The NGL Truck System Work

Exactly as the customer needed it to. Part of the process in ensuring a successful outcome for this compressor skid project was to ask the right questions up front. What, How, Where, When are the basic need to knows.

What is being moved: from a railcar to a tank, a tanker to a bullet tank, etc.

How do we need it to be moved: compressor or pump and the rate.

Where is the project: cold weather times, high heat, and daily extreme fluctuations.

When will it be moved: will there be an influx of tankers, railcars etc. is dual sided options needed.