Equip your CNG system with the Parker Finite advantage
Compressed Natural Gas (CNG) and atmospheric air have different masses because they are composed of different molecules and have different densities. CNG is stored under high pressure (usually between 2000 to 3600 psi), which significantly increases its density compared to atmospheric conditions. Under compression, there is more oil carryover and contamination. Inter-stage filtration is recommended for compressors with multiple stages to eliminate the risk of oil aerosols traveling downstream.
Using Parker Finite filtration between the compressor stages prevents oil carryover into the storage tanks. When sizing filters, it is important to understand the pressure and flow profile of the output to compensate for, and dampen, pulsations.
What is Oil Carryover?
- Compressor oil bypassing the piston rings in multi-stage compressors
- Small aerosols are formed from the shear action of the rings sliding against the cylinder walls
- Aerosols and vapors get entrained and suspended in the gas flow and travel downstream
After a cycle of compression in a multi-stage compressor, the pressure increases requiring filter housings suitable for those elevated pressures. It is critical to remove contaminants and oil carryover to avoid common issues:
- Compressor fouling
- Vehicle fuel system repair
- Liquids in storage tanks
- Gas dispenser replacement
Distribution Panel and Cascade or Buffer Storage Tanks
It becomes very difficult to get oil out of tanks once contaminated. Any oil in these storage tanks is at risk of migrating downstream ultimately to the dispenser and into the vehicle tank. Using multi-stage Parker Finite filtration (Grades 10C followed by 4C) between the compressor and the tanks is key to preventing oil carryover into the tanks.
Ensuring that properly sized two-stage filtration is in place after the compressor and before the tanks is the best system design to keep the tanks dry and oil-free. Grades 10C followed by 4C in properly sized filters will prevent compressor oil carryover from getting into the tanks.
Priority Panels and Underground Lines
During light to normal usage periods the gas will travel from the compressor through filtration and into the storage tanks. There the gas can cool and travel out through the priority panel and post tank filtration and across the underground lines to the dispensers. During busy times (e.g., end of the day, refilling the fleet), the priority panel directs the gas to bypass the tanks and go straight from the compressor, through the priority panel and underground to the dispensers. This is when the system at most risk of compressor oil carryover.
Our studies have shown that two stages of Finite grade 4C filters right after the priority panel will capture fine oil aerosols from compressor oil carryover before the gas goes underground to the dispensers. This application has been specially designed for CNG, alternative fuel, high-pressure gases and air with CRN certification up to 6000 PSIG.
WATCH VIDEO
Fast Fill Compressors
The inlet of the compressors usually have a large a H Series housing with a particulate element for the incoming gas. From there, as pressures increase the progression will go from H Series to M Series to J Series. To dampen pulsations right after the compressor many OEMs use a large filter housing (2" ports with Grade 10C) followed by a smaller filter housing (1" ports with Grade 4C).
Featured Filters
High pressure compressors are used in a variety of applications. Many owners, operators and designers of high pressure compressed air or gas systems rely on Finite for high-quality air treatment filters to remove contaminants and to keep their systems running smoothly.
H Series
Our Finite H Series filter eliminates oil, water, and particulate contamination from large flows of compressed air and gas. Extremely versatile, this series offers coalescing, particulate and adsorption filter elements as well as optional indicators, gauges and drains.
- Max Pressure 500 PSIG
- Port Sizes 1.5" to 3"
- Max. Temp: 450°F
- Min. Temp: -20° F
- Certifications CRN
- Threads: NPT
- Material: Aluminum
- Plating: Chromate
M Series
Varied porting and connection styles, along with a robust design makes the M-Series an extremely versatile filter. It is a perfect fit for interstage filtration applications for multistage, high pressure gas compressors and is compatible with special gases such as argon, hydrogen, CNG and helium.
- Max Pressure: 800 PSIG
- Port Sizes 1/4" to 1", 2"
- Max. Temp. 175°F
- Min. Temp. -20° F
- Threads: NPT
- Material: Aluminum
- Plating: Chromate
J Series
J-Series Filters eliminate rust, pipe scale, compressor lubricant oil, and water from compressed gases. They are ideal in high pressure CNG systems, not only as inter-stage filters in the multi-stage compression of the gas, but also in the storage and delivery of the gas for CNG powered vehicles.
- Max Pressure 5000 PSIG
- Port Sizes: 1/4" to 2"
- Max. Temp.: 350° F
- Min. Temp.: -40° F
- Threads: NPT or SAE
- Material: SG Iron
- Plating: Electroless Nickel
CJ Series
- Max Pressure: 2550 PSIG
- Port Sizes: 1/4" to 2"
- Max. Temp.: 350° F
- Min. Temp.: -40° F
- Certifications: CRN
- Threads: NPT or SAE
- Material: SG Cast Iron
- Plating: Electroless Nickel
Featured Filter Elements
Parker offers an array of Finite filters sized to handle any natural gas flow and several media choices to meet natural gas application demands. ASME filter housings are constructed from carbon steel. Choices of filter media types include glass fiber for coalescing liquids, cellulose for particulate removal and activated carbon materials for oil vapor and hydrocarbon removal. Filter element ratings are available from 100 micron down to 0.01 micron.
Coalescing Filter Very High Efficiency - Media Type 4C, 6C, 10C
Parker manufactures its Finite Uni-Cast coalescing elements using a proprietary Parker formation process for high efficiency, graduated density, depth filtration. These rugged elements composed of an epoxy saturated, borosilicate glass microfiber tube in intimate interlocking contact with a rigid retainer and surrounded by a coarse fiber drain layer. This element has a unique graduated density that makes it very effective from removing very fine aerosols and compressor oil carryover from natural gas streams.
Coalescing Filter Heavy Duty - Media Filter Type 7CVP
Coalescing element made of pleated glass media. Metal retained for added strength. Includes metal end caps and fluorocarbon gaskets for proper sealing. Only available in Grade 7.
Liquid Separator - Media Type 100 WS
This all stainless steel element is designed to remove aerosolized liquid droplets from the gas stream. It has two metal retainers with rolled mesh screen in between. This cleanable element combines liquid droplets and aerosols, separating the liquids from the gas stream in systems with high liquid loads.
Dry Particulate Filter - Media Type 3P
Pleated cellulose particulate removal element. Includes molded elastomeric end seals (3PU). Some models offer the option of metal end caps and fluorocarbon gaskets.
Finite Filtration Resources
Looking to find more details about Finite filtration solutions? We've compiled helpful resources including literature, videos and blogs in one place, making it easy to quickly learn more about our products.
Have a Question?
We are happy to help. Contact us today to discuss your application or learn more about Finite filtration.