One package. 150 to 600 psig in. CNG fill pressure out.
The 3-stage NuPresto 400 covers the full 150 to 600 psig suction window in a single configuration. Same Fornovo DA300 frame and controls philosophy as the 2-stage, with the staging and cooling needed to handle low and mid-range pipeline and RNG inlet pressures.
Overview
The 3-stage NuPresto 400 is built for jobs where pipeline or RNG inlet pressure sits anywhere from 150 to 600 psig and CNG discharge still has to land at 4,200 psig. Three compression stages, three intercooler sections and a final aftercooler keep stage temperatures and ratios inside the design envelope across the entire suction range, without forcing you to specify a separate booster or pick between sub-configurations.
Mechanically it is the same NuPresto 400 platform: Fornovo Gas DA300 frame, non-lubricated water-cooled cylinders, PLC controls and full FAT in shop.
Key specifications
| Compression stages | 3-stage |
|---|---|
| Compressor frame | Fornovo Gas DA300 heavy-duty reciprocating |
| Cylinders | Non-lubricated, water-cooled, with HP valves |
| Suction pressure | 150 to 600 psig |
| Discharge pressure | Up to 4,200 psig |
| Flow rate | Up to 2.6 MMSCFD |
| Driver | 300 to 400 HP electric motor (depends on suction pressure), 1,200 rpm |
| Interstage cooling | 3-section air cooler plus jacket water circuit |
| Discharge treatment | Interstage scrubbers and final discharge coalescer |
| Cooling package | Closed-loop glycol with multi-fan air cooler |
| Control system | PLC-based with HMI, remote monitoring via Ewon |
| Lube oil | Chevron Cetus PAO 68 or approved equivalent, shaft-driven lube oil pump |
| Design standards | ASME Section VIII Div. 1, B31.3, NEC, NFPA, API and ISO |
| Skid | Single skid, fully assembled and FAT-tested in shop |
Overlap at 550 to 600 psig suction: engineering will recommend the better fit based on inlet stability and target flow. Detailed performance curves are not published; contact engineering for sized performance.
2-stage vs 3-stage at a glance
| Variant | Suction | Flow | Best fit |
|---|---|---|---|
| 2-Stage | 550 to 900 psig | Up to 3.64 MMSCFD | High-pressure pipeline mother stations |
| 3-Stage | 150 to 600 psig | Up to 2.6 MMSCFD | RNG and low to mid-pressure pipeline service |
| 4-Stage | 40 to 100 psig | Up to 1.1 MMSCFD | Declining wells, low-pressure RNG, stranded gas |
Why NuPresto 400 3-Stage
One configuration, wide operating window
From RNG dryer outlets at 150 psig up to mid-pressure pipeline taps at 600 psig, the 3-stage covers it. No need to specify a sub-variant or commit to a narrow operating band on day one.
Three-section air cooler
Engineered air cooler with separate sections for each stage discharge plus jacket water. Stage temperatures stay inside the design window even at 100 °F ambient and 3,000 ft elevation.
Same frame, same controls, same service plan
Identical Fornovo DA300 bottom end, control philosophy, HMI and remote monitoring as the 2-stage. Same maintenance intervals, same spares stocked at our shop. Operators trained on one variant are trained on both.
Non-lubricated cylinders
No oil carryover into the gas stream. Cleaner downstream equipment, less environmental risk, simpler permitting.
Engineered for continuous service
Interstage scrubbers, pulsation control and ASME-stamped vessels and coolers sized for 24/7 RNG and CNG mother station duty.
Built and tested in shop
Final assembly, FAT, loop checks and HMI commissioning happen in our shop. Issues get caught in the shop, not on your site.
Typical applications
- RNG-to-CNG mother stations off RNG dryer outlets
- Low and mid-pressure pipeline taps and lateral compression
- CNG fueling sites where inlet pressure is unstable or seasonally variable
- Virtual pipeline trailer filling (pairs with NuBlu VPT-64 and VPT-128)
- Wellhead and field gas compression with CNG offtake
- Replacement of aging multi-stage CNG packages on existing pads
What's included
- Single skid with 3-stage compressor, motor, multi-section air cooler and process piping
- Inlet filter, three interstage scrubbers and final discharge coalescer
- Closed-loop glycol cooling system with jacket water circuit
- PLC, HMI and field instrumentation, wired and tested
- Cause-and-effect diagram, control narrative and FAT package
- ASME-stamped pressure vessels and coolers, B31.3 piping
- Installation, commissioning and start-up procedure
- Recommended spare parts list and pricing
Engineering and aftermarket support
Every 3-stage NuPresto 400 ships with a complete engineering package: P&IDs, GA drawings, electrical load lists, lifting and torsional analyses and a full O&M manual. Critical spares, including complete cylinders, are stocked at our shop for fast response.
Field service, troubleshooting and remote diagnostics are handled by the same team that designed and built the unit.