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Providing Innovative Product-Transfer Solutions for a Variety of Markets and Applications

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Blackmer HDL372 Reciprocating Gas Compressor Skid

HD370 Series Reciprocating Gas Compressors HD372, HDL372, HD373, HDL373

Designed with both air-cooled and liquid-cooled models, the Blackmer HD370 Series two-stage reciprocating gas compressors feature flow rates of 24.1 CFM (40.8 m³/hr) at max rpm. The HD370 Series gas compressors have four models available, the air-cooled (HD372/373), and liquid-cooled (HDL372/373) models. For precise leakage control and to minimize product contamination, the HD370 Series gas compressors offer double- (HD372/HDL372), or triple-seal (HD373/HDL373) models. Compared to competitive compressors, all HD Series Compressors are equipped with thicker and more robust wear parts – piston rings, needle bearings, and high-efficiency valves that will keep the HD Series compressors operating longer than the competition between maintenance cycles. Equipped with an array of features such as a ductile iron head and cylinders, steel pistons and self-adjusting piston rod seals, HD compressors provide maximum performance, energy efficiency, quiet operation, low maintenance cost and reliability under the most severe service conditions.

Performance and Specifications

Two-Stage Models

Double-Seal Triple-Seal HD372 / HDL372
HD373 / HDL373
1st Stage 2nd Stage
# Cyl. per Stage 1 1
Bore, in. (mm) 4.625 (117) 2.687 (68)­
Stroke, in. (mm) 3.0 (76)  
Maximum Allowable Working Pressure - psia (bar)   615 (42.4)
Minimum/Maximum rpm 350 / 825  
Piston Displacement
@100 rpm - CFM (m³/hr)
@Min rpm - CFM (m³/hr)
@Max rpm - CFM (m³/hr)

2.92 (4.96)
10.2 (17.3)
26.1 (40.8)
Max. Power, BHP (kW) 15 (11)
Wt. w/Flywheel, lb. (kg) ˜405 (184)
Inlet / Outlet NPT, in. 1.25/1.00

Features and Benefits

  • Two-stage models with piston displacements to 26 cfm (40 m3/hr) and working pressures up to 615 psi (42 bar) for use on higher compression ratio requirements
  • Available in air-cooled or liquid-cooled models
  • Available with double- and triple-seal models, providing positive sealing under all operating conditions with materials to suit any application
  • Triple-seal models are well suited for handling toxic, hazardous or corrosive gases


  • Vapor recovery
  • Gas gathering
  • Gas transfer
  • Gas evacuation
  • Enhanced recovery
  • Gas blanketing
  • Pressure boosting
  • Flare elimination
  • Leak test recovery
  • Liquid gas transfer

Common Industrial Gases:

  • Ammonia
  • Argon
  • Butadiene
  • Butane
  • Carbon Dioxide
  • Chlorine
  • Ethane
  • Ethyl Alcohol
  • Helium
  • Hydrogen
  • Hydrogen Chloride
  • Isobutene
  • Methyl Chloride
  • Nitrogen
  • Nitrous Oxide
  • Propylene
  • Refrigerants
  • Sulfur Dioxide
  • Vinyl Chloride

Visit the Compressor Solutions page for more information about the HD Series Reciprocating Gas Compressors.
Learn more about Blackmer Reciprocating Compressors with our interactive tool.


Options Available Literature  Details
Crankcase Oil Heater CB322 Used to maintain adequate oil temperature in cold to severe climates 
Distance Piece Options CB037 Section of gas compressor between crankcase and compressor cylinder that isolates the two areas, providing oil-free operation for cylinder 
Pressure Gauges CB105 Various pressure gauges available
Suction Valve Unloaders & Systems CB039 Prevents the compression of gas in the cylinder by holding the suction valves open, allowing the compressor to be started without a load and to control compressor's capacity
Wear & Corrosion Resistant Compressors (TNT-12) CB001 Wear and corrosion resistant treatment for compressor, with TNT-12 impregnated parts
O-Ring Materials    Optional O-ring materials include PTFE, FKM, Neoprene, Ethylene-Propylene 
Alternate Piston Ring Materials    Optional Piston-ring materials include poly filled PTFE 
Extended Crankshaft    Extended crankshaft available for direct drive mounting 
Oversized Flywheels    Available for various drive options 

Ancillary Equipment

Equipment Available Literature  Details
4-Way Valves CB046 For piping, in aiding for easy transition from liquid transfer to vapor recovery - comes with handle and flow indicator
Electrical Schematic CB276  Overview of a generalized wiring schematic for typical installations
Float Switch Information CB145 Activates alarms and/or shut-down equipment when a liquid rises or falls past the switch
Liquid Traps CB212 Trap installed in the suction line to stop liquid from entering the compressor
Liquid Traps, ASME Code CB218  ASME coded trap installed in the suction line to stop liquid from entering the compressor
Low Oil Pressure Switches  CB020  Sends signal when the compressor's crankcase oil pressure falls 
Mounting Arrangements  CB111  A variety of mounting arrangements available for compressors 
Strainer CB172  Features a 30-mesh stainless steel screen 
Belt Guards    Available in either aluminum or stainless steel 
Pressure Switches    Activates alarms and/or shutdown equipment for suction, discharge, differential, and/or oil pressure 
Temperature Switches    Activates alarms and/or shutdown equipment for discharge and/or oil temperature 
Temperature Gauges    Visual confirmation of temperature - typically on the suction and discharge process gas location 
Thermowells    Protects temperature monitoring devices from harsh process gas conditions 
Control Panels and Starters    Junction box and full turn-key functionality available in required classifications 
NPT or Welded Piping Systems    Threaded or welded steel piping systems 
Pressure Gauges  CB105  Visual confirmation of pressure - typically on the suction, discharge, and oil locations 
Receivers    Often times used as a holding vessel for pressure control on the suction or discharge 
Relief Valves    Overpressure safety devices required on the compressor discharge and any associated ASME code vessels 
Shutoff Valves    Available in either manual or powered 
Aftercoolers    Available in either air or water cooled 
Motor or engine drives    Available in various classifications and fuel types 
Repair tool kits  CB110  List of part numbers for special tools and tool kits used on compressors 
Unloader Solenoid Valve CB315 
3-way solenoid suction valve unloader control 

Maintenance Tools

Maintenance Tools – HD372C, HDL372C, HD373C, HDL373C Part Number
Packing Installation Tool 790536
Spanner Wrench, 1/4" Adjustable 790316
Wrench for Valve Holdown Screw 790535
Compressor Tool Kit 790199
Valve Tool 798016
Piston Tools 798009/798010
Packing Ring Tool 798015


View the Blackmer Compressor maintenance videos here


Installation Operation Manuals (IOMs)

HD172C, HD173C, HD372C, HD373C, HDL172C, HDL173C, HDL372C, HDL373C

Spec Sheets

Materials of Construction

All HD Series Models