Natural Gas Compressor

Q: Why is water injection used in screw compressors for natural gas?

Water injection serves three critical functions in natural gas compression: (1) cooling — keeping discharge temperature below 45°C eliminates ignition risk when compressing flammable gas; (2) sealing — water fills the clearance between screw rotors for higher volumetric efficiency; (3) cleaning — water washes away contaminants that could foul the compression chamber. Isothermal compression also reduces energy consumption.

RAYDAFON natural gas compressors use water-injected screw technology with 304/316L stainless steel wetted parts, keeping discharge temperatures below 45°C for safe handling of flammable gas. API 618 and API 11P compliant designs serve pipeline transmission, CNG fueling stations, coalbed methane recovery, and refinery gas processing. Explosion-proof certified. Factory-direct supply from Ningbo, China.

Send Inquiry

Product Description

What Is a Natural Gas Compressor and Why Does Industry Need It?

A natural gas compressor increases gas pressure by reducing volume, enabling transportation through pipelines, storage in underground reservoirs, and fueling of CNG vehicles. The global natural gas compressor market was valued at US$ 992 million in 2025 and is projected to reach US$ 1,157 million by 2032, driven by pipeline infrastructure expansion, LNG terminal construction, and coalbed methane recovery projects worldwide.

API 618 Compliant Water-Injected Screw ≤45°C Discharge Temp Explosion-Proof Certified

Natural gas compression differs fundamentally from air compression. Methane is flammable, and conventional oil-lubricated compressors risk ignition if discharge temperatures exceed the gas's autoignition threshold. RAYDAFON addresses this through water-injected screw technology — water injection keeps compression chamber temperatures below 45°C, while the piston compressor cavity typically exceeds 100°C during operation, creating safety risks. Water injection also provides sealing and cleaning functions, achieving near-isothermal compression that reduces energy consumption.

RAYDAFON water-injected screw natural gas compressor for pipeline and CNG station applications — Figure 1: RAYDAFON water-injected screw natural gas compressor — 304/316L stainless steel air end with explosion-proof certification

Working Principle: How a Water-Injected Screw Natural Gas Compressor Operates

RAYDAFON natural gas compressors use a water-injected twin-screw air end as the core compression element. Unlike oil-injected or dry-running compressors, water serves simultaneously as coolant, sealant, and cleaning agent within the compression chamber.

Gas intake: Natural gas enters the compression chamber through a high-efficiency intake valve at suction pressure. The patented lowest-point air intake design improves compression efficiency and reduces suction noise.
Water injection: Purified water is injected directly into the screw mesh point. The water absorbs compression heat immediately, maintaining chamber temperature below 45°C throughout the compression cycle.
Isothermal compression: The twin screws rotate to reduce chamber volume, compressing the gas. Water fills clearances between rotors, minimizing gas leakage and achieving higher volumetric efficiency than dry-running designs.
Water-gas separation: The compressed gas-water mixture enters a stainless steel separation barrel. The internal streamlined design allows the gas flow to reach 10 m/s, ensuring complete moisture separation. Water settles to the bottom while dry gas exits through the minimum pressure valve.
Cooling and discharge: A high-performance plate heat exchanger cools the circulating water, keeping outlet temperature below 55°C. The cooled gas discharges at the required pressure for downstream pipeline or storage use.

Technical Specifications

Parameter	Specification
Compressor Type	Water-injected screw / Reciprocating
Design Standard	API 618 5th Edition / API 11P / ISO 13631
Working Pressure	Customizable (0.1 MPa to 25 MPa depending on configuration)
Discharge Temperature	≤45°C (water-injected screw); ≤140°C (reciprocating, API 618 limit)
Wetted Material	304 stainless steel (standard); 316L (optional)
Explosion-Proof Rating	ATEX / IECEx certified for Zone 2 hazardous areas
Motor Protection	IP55, Insulation Class F, SKF bearings
Control System	PLC with HMI touchscreen; Schneider Electric control system
Power Range	50-5,000 HP (customizable)
Certifications	CE, ISO 9001, Explosion-Proof Certification

Reciprocating vs. Water-Injected Screw: Which Type Fits Your Application?

The choice between a reciprocating and a screw natural gas compressor depends on your pressure ratio, flow profile, and gas composition. Reciprocating units excel at high compression ratios and variable gas streams, while water-injected screw compressors are preferred for flammable gas safety and continuous duty.

Water-Injected Screw Compressor

Discharge temperature ≤45°C — eliminates ignition risk
Near-isothermal compression — lower energy consumption
Oil-free design — no oil carryover contamination
Continuous duty — 24/7 fault-free operation
Compact skid-mounted design — easy installation
Best for: coalbed methane, CNG stations, biogas, refinery gas

Reciprocating Compressor

High compression ratio — up to 10:1 per stage
Excellent turndown — 10-100% with VSD
Handles dirty or variable gas compositions
Proven reliability in pipeline transmission
Higher pressure capability — up to 800+ bar
Best for: pipeline transmission, gas storage, high-pressure injection

Industry Applications

Pipeline Transmission & Gas Gathering

Booster compressors maintain pressure along transmission pipelines, overcoming friction losses as gas travels hundreds of kilometers. Reciprocating units handle fluctuating wellhead pressures as reservoirs deplete, maintaining high compression ratios across stages. China's first fully domestically-produced 20 MW pipeline compressor set recently passed 72-hour trial operation at the Shaanxi-Luoyang station on the West-East Gas Pipeline, achieving 20.7 MW maximum power.

CNG Fueling Stations

CNG mother stations and daughter stations require compressors that pressurize natural gas from pipeline pressure (typically 0.3-1.5 MPa) to vehicle storage pressure (20-25 MPa). API 11P compliant compressor packages with inter-stage pulsation damping provide the reliability required for continuous fueling operations.

Coalbed Methane (CBM) Recovery

Coal mine gas recovery captures methane that would otherwise be vented to atmosphere. Water-injected screw compressors recover and pressurize this gas for energy utilization, recycling energy while significantly reducing environmental pollution. Suction pressures as low as 0.1 MPa are handled by skid-mounted packages.

Refinery & Petrochemical Gas Processing

Refineries, natural gas chemical plants, vinylon plants, and chemical fiber facilities use natural gas compressors for process gas recovery, LPG recovery at liquefied gas stations, and strategic petroleum reserve depot vapor recovery. The explosion-proof design is mandatory for these Zone 2 environments.

Underground Gas Storage

Underground storage facilities inject and withdraw natural gas seasonally. When inlet pressure drops from 200 bar to 30 bar as reservoirs deplete, reciprocating compressors maintain the required compression ratio where centrifugal units would require multiple casings or gearboxes.

RAYDAFON natural gas compressor package for CNG station and pipeline booster applications — Figure 2: Skid-mounted natural gas compressor package with explosion-proof motor, PLC control, and stainless steel water-gas separation barrel

Why Water Injection Is Critical for Natural Gas Safety

Natural gas compression presents a unique safety challenge: the gas is flammable, and conventional oil-lubricated compressors operate at discharge temperatures above 100°C — dangerously close to the autoignition temperature of methane. Water injection solves this fundamentally.

Ignition risk elimination — Discharge temperature remains below 45°C, providing a safety margin well below methane's autoignition threshold. This is not a partial improvement but a fundamental safety barrier.
Isothermal compression efficiency — Water absorbs heat instantly at the compression point, achieving near-isothermal conditions that reduce energy consumption compared to adiabatic compression.
Hermetic sealing — Water fills the clearance between screw rotors, minimizing gas leakage and maximizing volumetric efficiency without oil-based sealing.
In-chamber cleaning — Water continuously washes contaminants from the compression chamber, reducing maintenance downtime and extending component life.
Oil-free gas purity — No lubricant contacts the gas stream. This eliminates oil carryover that could foul downstream equipment or violate gas purity specifications.

Natural Gas Compressor Configuration Guide

Configuration	Typical Application	Pressure Range
Water-injected screw (standard)	Coalbed methane, biogas, refinery gas	0.1–0.7 MPa suction; up to 1.6 MPa discharge
Water-injected screw (high-pressure)	CNG station, LPG recovery	Up to 25 MPa discharge
Reciprocating (pipeline booster)	Gas transmission, gas gathering	Up to 100 bar discharge
Reciprocating (high-ratio)	Underground storage, injection	Up to 800 bar discharge

Pricing depends on configuration, working pressure, flow capacity, and explosion-proof certification requirements. Share your suction pressure, discharge pressure, and gas composition — RAYDAFON will respond with a factory-direct quote within 12 hours.

Why Choose RAYDAFON as Your Natural Gas Compressor Manufacturer

15+ Years of Special Gas Compression Experience — RAYDAFON Technology Group has served the compressed gas industry since 2009, with products deployed across oil and gas, petrochemical, and energy sectors in 40+ countries.
API 618 & API 11P Design Compliance — All compressors designed and tested to API 618 5th Edition and API 11P standards, with third-party inspection reports available on request.
Water-Injected Screw Technology — Proprietary air end design keeps discharge temperature below 45°C, providing the safety margin essential for flammable gas compression.
Food-Grade Material Standard — 304 stainless steel air end as standard, 316L available for corrosive gas compositions. All gas-contact piping in stainless steel.
100% Performance Testing — Every unit tested for leak integrity, pressure stability, vibration, and proper operation before shipment. Test reports available.
Factory-Direct Pricing — No trading-company markup. Direct engineering communication for technical selection and after-sales support.

Frequently Asked Questions

What is a natural gas compressor used for?

A natural gas compressor increases gas pressure for pipeline transmission, CNG vehicle fueling, underground gas storage, coalbed methane recovery, refinery gas processing, and LPG recovery. Compressors are essential wherever natural gas must be moved, stored, or processed at elevated pressures.

What is the difference between a reciprocating and a screw natural gas compressor?

A reciprocating compressor uses a piston to compress gas in discrete pulses, excelling at high compression ratios (up to 10:1 per stage) and variable gas compositions. A water-injected screw compressor uses rotating screws with water injection for near-isothermal compression, keeping discharge temperatures below 45°C. Screw compressors are preferred for flammable gases because the low temperature eliminates ignition risk.

What safety certifications do RAYDAFON natural gas compressors carry?

RAYDAFON natural gas compressors are designed to API 618 and API 11P standards with explosion-proof motors and electronic controls. They carry CE certification and comply with IECEx/ATEX requirements for Zone 2 hazardous areas.

Why is water injection used in screw compressors for natural gas?

Water injection serves three critical functions: (1) cooling — keeping discharge temperature below 45°C eliminates ignition risk; (2) sealing — water fills the clearance between screw rotors for higher volumetric efficiency; (3) cleaning — water washes away contaminants. Isothermal compression also reduces energy consumption.

What is the typical delivery time for a natural gas compressor?

Standard configurations ship within 25-45 days from order confirmation. MOQ is 1 unit. Custom-engineered skid-mounted systems may require 50-70 days depending on design complexity. We accept sample orders for validation testing.

Related Equipment

For a complete special gas compression system, pair your natural gas compressor with:

CO2 Compressor — For transcritical refrigeration, carbonation, and CCS applications
Hydrogen Compressor — For green hydrogen production and refueling stations
Full Special Gas Range — Nitrogen, argon, helium, and other process gases

Ready to Specify Your Natural Gas Compressor?

Share your suction pressure, discharge pressure, and gas composition — our engineers will reply with a factory-direct quote within 12 hours.

Request Quote Now

Hot Tags: natural gas compressor , natural gas compressor station , compressed natural gas compressor , compressor station natural gas , natural gas air compressor , natural gas compressor companies , natural gas compressor diagram

Related Category

Send Inquiry

Contact Info



Address

Luotuo Industrial Area, Zhenhai District, Ningbo City, China


Tel

+86-574-87167707


Email

[email protected]

Raydafon: Your One-Stop Service Provider for High-End Gas Equipment. From oil-free compression to PSA gas purification, we utilize cutting-edge technology to ensure reliability, offering a complete gas solution for industries with strict requirements for purity and performance.

Get the quote immediately and obtain your personalized gas solution!