Vapor Recovery Unit Systems

What makes vapor recovery difficult?  Isn’t it just a small compressor?

Upstream pressure in atmospheric tanks is limited to a window of between 0.4 oz. / sq. in. and 4 oz. / sq. in. The reason for this is a vacuum break and pressure safety valve arrangement must be installed in all atmospheric tanks to protect them from overpressure or vacuum. Which these tanks are not designed for. When the tank is opened to the atmosphere or liquid product is drawn out the compressor intake must shut off immediately to prevent Oxygen from being drawn in and creating an explosive mixture.
Then when vapor reaches 0.4 oz. / sq. in. inside the tank, the compressor must resume recovery without human interaction. And do it reliably every time.  The gas collected from storage tanks is very rich and wet. Great for sales but VERY bad for compressors! RECIPROCATING COMPRESSORS WILL NOT SURVIVE THESE CONDITIONS! The compressor system has to be designed such that condensates do not form in the compressor damaging its internals.  Downtime must be kept to a minimum. Any time the VRU is down there are Hydrocarbon emissions that must be accounted for. AND, ASSOCIATED LOST GAS IS LOST REVENUE!

THE “HIGHLY CONTROLLED” WAY-

Transducers, PLCs, VFDs, Valve positioners, instrument gas systems and more. Each component creating a potential point of failure. Do they work? Yeah… They work great when they work. BUT when there is a problem diagnostics and repair are a nightmare!  These systems are VERY expensive. Both to purchase and maintain.

We determined that “THERE HAD TO BE A BETTER WAY!”

How is Scorpion Systems doing it?

We use a simple pressure-controlled regulator setup that controls the tank vapor pressure to within the desired window and controls when vapor is taken from the tank vent very reliably WITHOUT ANY PLCs or VFD speed controls or bypass needed. We use an Encapsulated Screw Compressor with a minimum of 80,000 hours bearing life that runs continuously to maintain an operating temperature that prevents condensate from diluting the Compressor Lube oil. Service is very simple and oil change intervals exceed 6 months of continuous operation. THE THING JUST RUNS!
Scorpion Vapor Recovery  Units are available for ANY flow rate or discharge pressure

vapor recovery systems
vapor recovery systems
vapor recovery systems

Scorpion VRUs

  • NO PLC NEEDED FOR PROCESS CONTROL
  • FEW POSSIBLE POINTS OF FAILURE
  • NO INSTRUMENT GAS SUPPLY NEEDED
  • NO VENTING VALVE ACTUATORS AND POSITIONERS
  • SIMPLE “PLUG AND PLAY” INSTALLATION AND STARTUP
  • NOT EASILY DAMAGED BY VOLTAGE SPIKES OR LIGHTNING
  • NO TRANSDUCER NEEDED ON TANK  OR VENT HEADER
  • FULLY HOUSED SYSTEM FOR WEATHER PROTECTION WITH COMPONENTS ARRANGED FOR EASY SERVICE
  • TROUBLESHOOTING IS SIMPLE AND STRAIGHTFORWARD
  • FEWER REPLACEMENT PARTS
  • CAPABLE OF HANDLING MULTIPLE INPUT STREAMS (TREATER AND TANK VENT) WITH NO MODIFICATION

Conventional VRUs

  • PLC CONTROLLED
  • HUNDREDS OF POSSIBLE POINTS OF FAILURE
  • INSTRUMENT GAS SUPPLY REQUIRED (or internal)
  • ACTUATORS AND POSITIONERS VENTED
  • PROGRAMMING AND “TUNING” TYPICALLY NEEDED ON STARTUP
  • VERY VULNERABLE TO VOLTAGE SPIKES AND LIGHTNING
  • TRANSDUCER MUST BE INSTALLED IN TANK VENT HEADER
  • OPEN GROUND LEVEL SKID
  • TROUBLESHOOTING IS COMPLEX AND OFTEN REQUIRES A PLC TECHNICIAN
  • MANY PARTS FROM MANY MANUFACTURERS
  • USUALLY LIMITED TO A SINGLE INPUT STREAM DUE TO CONTROL DESIGN CONSTRAINTS

All of Scorpions fabricated systems are engineered and meticulously fabricated to our customer’s specific requirements, fully tested at our facility and shipped ready to go to work for you.