Description
L Series High Pressure Natural Gas Compression — Two-Stage and Three-Stage Reciprocating Process Service
The L Series high pressure natural gas compressor covers capacities from 6 to 25 m³/min at discharge pressures from 1.80 to 3.60 MPa. Verified models include both two-stage and three-stage configurations. At these pressure levels, multi-stage compression is the engineering standard: distributing the overall pressure ratio across two or three stages keeps each individual stage within manageable temperature limits and improves the overall efficiency of the compression process.
Several L Series high-pressure models operate on a 380 V electrical supply — a characteristic that distinguishes them from the large D and H Series low-pressure machines, and from some of the higher-capacity high-pressure units in this product line. For projects where high-voltage electrical infrastructure is limited, the availability of 380 V high-pressure L Series models represents a practical consideration in the equipment selection process.
Operating Range
Discharge Pressure Range (verified models): 1.80 – 3.60 MPa
Capacity Range (verified models): 6 – 25 m³/min
Stage Configuration: Two-stage (at 1.80 MPa); three-stage (at 3.00–3.60 MPa)
Driver Power Range: 65 – 280 kW
Electrical Supply: 380 V (most models); 380/6K or 10K on selected models
Capacity values are in m³/min as stated in the source data. The flow-reference basis (actual, standard, or normal conditions) must be confirmed with the engineering team for accurate North American sizing. Pressure values are as stated; gauge/absolute basis should be verified for engineering use.
Available Models and Technical Specifications
| Model | Configuration | Capacity (m³/min) | Discharge Pressure (MPa) | Dimensions L×W×H (mm) | Weight (t) | Power (kW) | Voltage |
|---|---|---|---|---|---|---|---|
| LW-6/18 | 2-row, 2-stage | 6 | 1.80 | 2050×910×2070 | 1.80 | 65 | 380 |
| LW-8/18 | 2-row, 2-stage | 8 | 1.80 | 2014×910×2006 | 1.80 | 75 | 380 |
| LW-10/18 | 2-row, 2-stage | 10 | 1.80 | 2632×1550×2332 | 3.00 | 110 | 380 |
| LW-16/30 | 2-row, 3-stage | 16 | 3.00 | 3500×2600×1850 | 6.00 | 220 | 380 |
| LW-20/30 | 2-row, 3-stage | 20 | 3.00 | 3500×2600×1850 | 6.00 | 240 (250) | 380 / 6K or 10K |
| LW-25/30 | 2-row, 3-stage | 25 | 3.00 | 2960×1685×2335 | 6.50 | 280 | 380 / 6K or 10K |
| LW-20/36 | 2-row, 3-stage | 20 | 3.60 | 4000×3100×2800 | 9.50 | 250 | 380 / 6K or 10K |
Capacity in m³/min as stated in source data; flow-reference basis must be confirmed. Pressure as stated; gauge/absolute basis should be verified. LW-20/30 lists 240(250) kW indicating optional motor variants. Three additional LW models (LW-60/2.5, LW-40/4, LW-50/5) from the low-pressure source table are under technical classification review and are not assigned here pending confirmation.
Why Stage Count Changes Across the Pressure Range
At 1.80 MPa discharge, the LW-6/18, LW-8/18, and LW-10/18 use two-stage compression within a two-row frame. Two stages can distribute the compression ratio from atmospheric suction to 1.80 MPa into two manageable steps. Each stage handles a partial pressure ratio, and gas is cooled between stages before entering the next cylinder. This keeps discharge temperatures and cylinder pressures within engineering limits for valve durability, ring life, and gas quality.
At 3.00 and 3.60 MPa, the models shift to three-stage compression. The higher discharge pressure means the overall compression ratio from near-atmospheric suction is larger, and distributing it across three stages further reduces the ratio at each individual stage. This is not a choice made purely for mechanical reasons — for natural gas, the per-stage temperature rise must be controlled to protect valves and rings and to prevent any risk of condensate formation or gas quality degradation between stages. Three-stage compression at 3.00–3.60 MPa discharge is the engineering approach that balances performance, mechanical reliability, and gas management across the compression train.
Interstage Cooling in Multi-Stage Compression
Between each compression stage, an interstage cooler removes heat from the gas before it enters the next cylinder. In a three-stage arrangement, there are two interstage coolers — one after the first stage and one after the second. Cooling the gas before it enters the next compression stage increases the gas density entering that stage, improving the mass flow the cylinder delivers per stroke. It also reduces the final discharge temperature of the last stage, which affects piping materials, discharge valve performance, and gas quality.
For the L Series high-pressure models, cooling method — air-cooled or water-cooled — is a project-specific parameter. Sites with access to cooling water may use water-cooled interstage coolers, which can achieve lower approach temperatures than air-cooled coolers in most ambient conditions. Air-cooled interstage cooling is standard practice where cooling water is not available, but the achievable interstage gas temperature depends on the ambient air temperature and cooler design. In high-ambient-temperature environments, the engineering team should evaluate the interstage temperatures to ensure the stage-inlet conditions are within the machine’s design parameters.
Process Applications
The L Series high-pressure range — 1.80 to 3.60 MPa discharge at 6 to 25 m³/min — fits process duties that require moderate gas volumes at substantial pressure elevation. Natural gas compressor applications at these pressures include gas gathering systems where field gas must be compressed to pipeline pressure for transportation, process gas compression within gas treatment plants where the treated gas must meet a delivery pressure specification, and pipeline boosting where the required delivery pressure is in the 1.80 to 3.60 MPa range.
At 6 to 25 m³/min, the L Series high-pressure machines are not suited to very high-volume pipeline or industrial applications — those duties are addressed by the higher-capacity D and 4M Series high-pressure units. The L Series covers smaller-volume applications where the gas volume is limited but the pressure requirement is substantial, and where the availability of 380 V electrical supply may be a site constraint.
Gas Composition and Suction Condition Requirements
At discharge pressures of 1.80 to 3.60 MPa, gas composition affects both the cylinder material selection and the compression behavior. Higher CO₂ content increases gas density and raises the molecular weight, affecting both the compression power requirement and the behavior of the gas at each interstage condition. H₂S, if present, raises corrosion concerns for cylinder bores, valves, piston rings, and associated piping — the concentration must be disclosed before a machine configuration can be finalized.
Suction pressure for the high-pressure L Series models is not specified in the source data and must be provided by the buyer. The actual suction pressure determines the real compression ratio from inlet to discharge. If suction pressure is already elevated — for example, gas arriving from a low-pressure compressor stage ahead of the L Series unit — the total ratio each stage must handle is lower, which may allow different cylinder sizing or stage distribution than an atmospheric-suction calculation would imply. Providing the suction pressure is therefore essential for accurate compressor selection.
Information Required for Compressor Selection
- Gas composition (full component breakdown)
- Methane, CO₂, and H₂S content
- Suction pressure and suction temperature
- Required discharge pressure
- Required flow rate and flow-reference basis
- Site ambient temperature range and altitude
- Continuous or intermittent duty
- Available electrical supply (voltage and frequency)
- Cooling method (air-cooled or water-cooled)
- Hazardous-area classification requirements
- Skid and package requirements
- Destination country and project location
Frequently Asked Questions
Why does the LW-20/36 weigh 9.50 tonnes when the LW-20/30 at the same capacity weighs only 6.00 tonnes?
The LW-20/36 reaches a higher discharge pressure (3.60 MPa vs. 3.00 MPa), which requires higher-pressure cylinder construction and a more substantial frame to handle the increased cylinder forces. The machine is also physically larger — 4,000 × 3,100 × 2,800 mm versus 3,500 × 2,600 × 1,850 mm — reflecting the heavier pressure-containing components required for the higher pressure duty. Higher discharge pressure generally requires stronger, heavier cylinder and valve assemblies and a larger frame to distribute the resulting mechanical loads.
Can the high-pressure L Series be used as a second stage after a low-pressure compressor?
Multi-stage compression across separate compressor units — using a low-pressure machine to bring gas to an intermediate pressure and then a high-pressure machine to reach the final delivery pressure — is a well-established practice in gas compression. Whether the L Series high-pressure units are suitable for use in this configuration depends on the specific intermediate pressure, gas temperature at the inlet to the high-pressure machine, required final delivery pressure, and gas composition. The engineering team should review the full compression train operating conditions before confirming a two-compressor configuration.
What determines whether two-stage or three-stage compression is needed for my operating condition?
The number of stages is primarily determined by the total compression ratio from suction to discharge. At a given suction pressure, higher discharge pressure means a higher overall ratio, and more stages may be needed to distribute this ratio within acceptable per-stage temperature limits. Gas composition also plays a role — gas with a higher specific heat ratio will produce higher discharge temperatures at the same compression ratio than a gas with a lower ratio, which may require an additional stage to keep temperatures controlled. The engineering team performs this evaluation for specific operating conditions; the stage arrangement shown in the table reflects standard configurations for the listed discharge pressures assuming typical suction conditions.
Request a Technical Proposal
To evaluate L Series high-pressure models for your compression duty, the engineering team needs gas composition, suction pressure and temperature, required discharge pressure, required flow rate and its reference basis, site ambient conditions, electrical supply, and cooling availability. With these parameters, the team reviews the compression ratio distribution across the confirmed stage configuration, selects the appropriate cylinder arrangement, and prepares a technical proposal covering equipment scope, package dimensions, power requirements, and delivery terms.
Related Compressor Products
- Z Series High Pressure Natural Gas Compressor — small-capacity multi-stage high-pressure service
- L Series Low Pressure Natural Gas Compressor — L Series models for low-pressure process service
