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Blackmer Oil-Free Gas Compressors
Models LB161, LB361, LB601 & LB942

Blackmer oil-free gas compressors deliver high efficiency in handling propane, butane, anhydrous ammonia and other liquefied gases. They are ideal for rail car unloading and vapor recovery applications. These single-stage, reciprocating compressors are designed to give maximum performance and reliability under the most severe service conditions. All pressure parts are of ductile iron construction for greater resistance to both thermal and mechanical shock. They are designed for ease of maintenance, with all components readily accessible.

Models are available with capacities from 7 to 125 CFM (11.9 to 212 m3/h) with working pressure up to 425 psia (2931 kPa).

Gas compressors for liquid transfer

Many liquid transfer applications can be handled more efficiently with a gas compressor than a liquid pump. They include unloading of transports and pressure vessels where system piping restricts flow and may cause a pump to cavitate; unloading of LP-gas from rail cars, and other installations that require an initial lift to the liquid.

How liquid transfer is accomplished

When transferring liquid, a compressor creates a slight pressure differential between the vessel being unloaded and the receiving tank. The suction stroke of the compressor piston draws in vapor and decreases the receiving tank pressure. The discharge stroke moves a measured volume of vapor at a higher pressure into the supply where it displaces an equal volume of liquid through a separate line into the receiving tank. Generally, the liquid flow rate will be 5 to 6 US gpm for each cubic foot of piston displacement (670-775 liters per cubic meter).

Gas compressors for vapor recovery

When the liquid transfer phase has been completed, a significant amount of product (vapor and liquid) is left in the tank car ( often 3% or more of the tanks capacity). Recovery of product with a compressor is a simple operation, where a compressor can quickly pay for itself.

How vapor recovery is accomplished

Vapor recovery is accomplished with the use of a four-way valve. By rotating the valve handle ninety degrees, gas flow is reversed and the vapor pressure within the supply vessel is reduced. At this point, remaining liquid vaporizes and is quickly recovered. As the tank pressure is drawn down further, remaining vapors are also recovered to an economical level. Recovered vapor is discharged into the liquid area of the receiving tank and then condensed back to a liquid state.

Standard Compressor Packages

Blackmer offers a variety of factory assembled compressor packages to fit most application requirements. Standard base mounted units are available in the following styles.
  • CO - Compressor Only Includes basic compressor with flywheel.
  • B - Base Mounted Unit Includes compressor, pressure gauges, formed steel base, V-belt drive with belt guard and adjustable motor base, less motor.
  • E - Extended Shaft Includes compressor with flywheel and extended crank shaft.
  • TU - Transfer Unit Includes compressor, pressure gauges, formed steel base, ASME code stamped liquid trap assembly (complete with relief valve and a NEMA 7 electric float switch for Propane service), V-belt drive with belt guard and adjustable motor slide base.
  • LU - Liquid Transfer/Vapor Recovery Unit Includes compressor, pressure gauges, formed steel base, liquid trap assembly with a mechanical float, inlet strainer, interconnecting piping, 4-way valve, V-belt drive with belt guard and adjustable motor base, less motor.
  • LC - Liquid Transfer/Vapor Recovery Unit Includes compressor, pressure gauges, steel base, ASME code stamped liquid trap assembly (complete with relief valve and a NEMA 7 electric float switch for Propane service), inlet strainer, interconnecting piping, 4-way valve, V-belt drive with belt guard and adjustable motor base, less motor.

 

Fabrication Services
Hwy 65 North, P.O. Box 376
Hampton, Iowa 50441
Telephone: 641.456.4802 • Fax: 641.456.4600
Fabrication Services