Views: 0 Author: Site Editor Publish Time: 2026-06-10 Origin: Site
Many buyers encounter two options when reviewing quotes for pressure reduction skids: single-stage and two-stage regulation. The price and structure differ, but suppliers often fail to explain which one your project actually needs. This article starts directly from Huayan’s PRMS product parameters to clearly explain the core differences between the two solutions.
Single-Stage vs. Two-Stage: Core Differences at a Glance
Comparison Item | Single-Stage Regulation | Two-Stage Regulation (Huayan Standard) |
Reduction steps | One step from high pressure to target pressure | Coarse adjustment + fine adjustment, two-step gradual reduction |
Outlet pressure stability | Obvious fluctuation when pressure differential is large | Two-stage buffering, stable and controllable outlet pressure |
Applicable inlet pressure | Suitable for medium/low inlet pressure (≤4 MPa) | Suitable for high inlet pressure, max. up to 21.8 MPa |
Temperature drop control | Temperature drop concentrated after regulation, may cause pipeline icing | Two-stage heat exchange disperses temperature drop; outlet temp ≥ –5°C |
Maintenance complexity | Simple structure, relatively convenient maintenance | One additional regulator set, but skid-integrated with orderly maintenance |
Typical applications | City medium-pressure pipeline terminals, small industrial gas users | CNG tube skid connection, high-pressure inlet after LNG vaporization, large industrial gas supply |
Why Does Huayan PRMS Default to a Two-Stage Design?
The reason is directly stated in the product parameters: Huayan PRMS has a maximum inlet pressure of 21.8 MPa. This value corresponds to the gas pressure range after discharging from a CNG tube skid (250 bar). If the pressure were reduced directly from 21.8 MPa down to the working outlet pressure of 0.2–1.6 MPa in a single step, the pressure differential across the single-stage regulator would be too large, compromising both regulation accuracy and service life. The two-stage design splits this pressure differential into two segments: the first stage handles the bulk pressure reduction, and the second stage provides precise pressure control. The two stages work together to maintain a stable outlet pressure under extreme conditions.
Key data: Two-stage pressure reduction + two-stage heat exchange keeps the outlet temperature ≥ –5 °C, preventing downstream pipeline frosting or freeze blockage caused by temperature drop after regulation.
Huayan PRMS Main Technical Parameters
Parameter | Value |
Flow range | 500 – 5,000 Nm³/h (customizable up to 10,000 Nm³/h) |
Max. inlet pressure | 21.8 MPa (working pressure 25 MPa) |
Outlet pressure range | 0.2 – 1.6 MPa (adjustable per operating conditions) |
Pressure reduction stages | Two-stage |
Heat exchange stages | Two-stage, heat exchange temperature 60–75 °C |
Outlet temperature | ≥ –5 °C |
Working temperature | –50 °C ~ 65 °C |
Main body material | SS304 stainless steel / 30CrMoLX |
Regulator valve brand | Emerson / Kimray (optional on request) |
Control system | Siemens PLC + SCADA remote monitoring, supports unattended operation |
Safety protection | Audible + visual dual alarms, emergency shut-off valve, safety relief valve |
Certification standards | ISO9001 / ISO14001 / CE / ASME / ADR |
Applicable media | CNG / vaporized LNG / natural gas |
Frame dimensions | 12192 × 2438 × 1400 mm (skid-integrated) |
How to Decide Which Option Your Project Needs?
One simple judgment method: look at the difference between your gas source pressure and the downstream gas pressure.
· Gas source from a CNG tube skid (≥200 bar) → Must choose two-stage
· Gas source from high-pressure section after LNG vaporization (>10 MPa) → Two-stage recommended
· Gas source from city medium-pressure network (≤4 MPa) → Single-stage can be evaluated
· Downstream requires multiple gas pressure levels (e.g., 0.4 MPa and 0.1 MPa simultaneously) → Two-stage recommended, second stage can be adjusted separately
If you are unsure, you can directly provide the incoming gas pressure and the target outlet pressure when making an inquiry. Huayan will issue a selection recommendation based on the actual operating conditions.
Application Scenario | Recommended Configuration | Gas Source |
CNG mother/daughter station | Two-stage PRMS | CNG tube skid (250 bar) |
LNG vaporization station | Two-stage PRMS | High-pressure gas after LNG vaporization |
City gas gate station | Two-stage PRMS | High-pressure transmission pipeline |
Industrial gas supply | Single-stage or two-stage depending on pressure | Medium-pressure industrial network |
Information to Confirm Before Purchase
· Incoming gas pressure (maximum value and normal operating value)
· Required outlet pressure (and allowable fluctuation range)
· Rated flow rate and peak flow rate
· Climatic conditions at the installation site (note if ambient temperature is below –10 °C)
· Whether SCADA interface or remote monitoring is required
Submit the above information via the official website inquiry form, and the Huayan technical team will provide a selection recommendation and quotation within 1–2 working days.
