Filtration separation systems in beverage, medical, and industrial settings often rely on nitrogen membrane separators to generate nitrogen on demand. If you are in the market for a used Green Air unit, you will likely encounter two listings with the exact same title-"Nitrogen Membrane Separator Medical/Industrial/Processors/Beverage"-and the exact same story. Both are used, both are from Green Air, and both were used in a high-demand draught beer system before being removed after the location went out of business. The difference is the price: one is listed at USD 1,500.00, the other at USD 800.00. That USD 700 gap is worth examining before you buy.
Quick verdict
Based on the available listed details, the lower-priced listing is the stronger buy. The two entries share the same brand, condition, dimensions, weight, pressure rating, and description. The higher-priced listing introduces no new specification, no extra part, and no condition note. When two listings describe the same membrane with the same details, the lower listed price becomes the deciding factor.
Comparison table
| Attribute | $1,500 Green Air Listing | $800 Green Air Listing |
|---|---|---|
| Brand | Green Air | Green Air |
| Condition | Used | Used |
| Length | 45 inches | 45 inches |
| Width | 6-8 inches | 6-8 inches |
| Weight | ~30 lbs | ~30 lbs |
| Pressure rating | 200 PSI | 200 PSI |
| Price | USD 1,500.00 | USD 800.00 |
Where each product wins
The lower-priced listing wins on cost. It matches the higher-priced listing in every listed attribute while costing less. The higher-priced listing has no unique advantage in the provided details; it carries the same title, brand, condition, and description, so you would be paying more for the same listed membrane.
Product notes
Green Air Nitrogen Membrane Separator - USD 1,500.00
This is the higher-priced Green Air nitrogen membrane listing. It was used to produce nitrogen for a high-demand draught beer system, matching the beverage and industrial separation profile. The listing title explicitly mentions Medical/Industrial/Processors/Beverage, so it is positioned for multiple filtration separation applications. A concrete reason to choose it is that it offers the same described specifications as the lower-priced listing while giving you a second purchase option. The limitation is that it costs more than the other listing without any extra accessory or specification-the listing covers the nitrogen membrane only, with no compressor or tanks.
Green Air Nitrogen Membrane Separator - USD 800.00
This is the lower-priced Green Air nitrogen membrane listing. It shares the same title and description as the higher-priced listing, so the concrete reason to choose it is the cost advantage: you get the same described membrane for less money. The listed condition is marked as used, which is expected for a unit pulled from a draught beer system. The limitation is that the unit was removed from a location that went out of business, so it has already been in service. As with the other listing, you receive only the membrane; a compatible compressor and tanks are not included.
Final choice by use case
If you are setting up a beverage nitrogen system or need a replacement membrane for medical or industrial processors and want the lowest listed price for the described Green Air unit, choose the lower-priced listing. It matches the higher-priced listing on every confirmed specification. If you are comparing two listings and cannot find any detail that separates them, the rational move is to go with the lower price.
