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
TROUBLE SHOOTING 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.
NO PLC NEEDED
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 VENT HEADER
FULLY HOUSED SYSTEM FOR WEATHER PROTECTION
TROUBLE SHOOTING IS SIMPLE AND STRAIGHTFORWARD
FEWER REPLACEMENT PARTS
CAPABLE OF HANDLING MULTIPLE INPUT STREAMS (TREATER AND TANK VENT) WITH NO MODIFICATION.
VAPOR RECOVERY UNITS (VRUs)
What makes vapor recovery difficult? Isn’t it just a small compressor?
Scorpion Vapor Recovery Units are available for ANY flow rate or discharge pressure.
Just tell us what you have and where you want to put it and we'll give you a reliable solution!
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 over pressure or vacuum. Which these tanks are not designed for.
When the tank is opened to 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.
How are “THEY” doing it?
The highly controlled way.
Transducers, PLCs, VFDs, Valve positioners, instrument gas systems and HUNDREDS of possible points of failure.
They work great when they work. BUT if there is a problem diagnostics and repair are costly and time consuming.
These systems are VERY expensive. Both to purchase and to maintain.
The “Cheap” way.
Typically the bare minimum that could be called a VRU. These are mostly Converted air compressors.
Reciprocating piston compressors ( Usually Quincy).
These systems typically use an on/off control method which means the compressor may never reach operating temperature and therefore becomes a condenser in wet tank gas applications. Condensate forms in the crank case and dilutes the lube oil causing oil pressure loss and catastrophic failure. Possibly fire!
THERE HAD TO BE A BETTER WAY!
How are “WE” 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.
Service is very simple and oil change intervals exceed 6 months of continuous operation.
THE THING JUST RUNS!