Polymer Separator Pressure Vessel for Uzbekistan Natural Gas Project | Design & Application

Raw natural gas extracted directly from underground reservoirs is not a pure, single-phase gaseous medium. Instead, it is mixed with a substantial amount of gaseous, liquid, and solid impurities, which represent the core engineering challenges that separators at gas field treatment stations must overcome.

Liquid impurities primarily consist of formation water, condensate, and heavy hydrocarbon fractions. Solid impurities are dominated by sand, rock debris, and iron sulfide carried over during extraction, while coalbed methane (CBM) often carries solid tar and silica particles. Gaseous impurities typically contain acidic, corrosive gases such as hydrogen sulfide (H2S) and carbon dioxide (CO2). These impurities originate from two sources: primary associated impurities that cannot be fully removed during extraction, and secondary pollutants generated during gas compression and long-distance pipeline transmission.

Whether dealing with oilfield gas, gas field gas, or coalbed methane, solid particulate matter is inevitably entrained during extraction, with impurity compositions varying significantly across different mineral regions. During long-distance transport, fine impurities continuously accumulate. Furthermore, as the natural gas is heated during compression, small amounts of methane and ethane undergo pyrolysis. Under specific temperature and pressure conditions, this process forms solid polymers that adhere to the inner walls of pipelines and equipment. This buildup easily leads to clogging, wear, and corrosion, which is the fundamental reason for custom-engineering the polymer separator pressure vessel for this Uzbekistan project.

Project Background: Introduction to the Uzbekistan Polymer Separator Project

Uzbekistan boasts abundant natural gas reserves. However, many of its gas gathering stations have long grappled with raw gas containing polymers, solids, and liquid impurities that far exceed allowable thresholds. The original, rudimentary separation equipment lacked sufficient separation accuracy. Consequently, solid polymers continuously accumulated, frequently clogging downstream compressors and heat exchange pipelines. This resulted in a high frequency of equipment maintenance and severely restricted the continuous, stable production of the gas stations.

After comparing domestic and international pressure vessel manufacturers, the client ultimately selected Shijiazhuang Zhengzhong Technology (Center Enamel) to customize a large-scale horizontal polymer separator engineered specifically for the region's high-polymer, sulfur-bearing raw gas conditions. Utilizing our dual design and manufacturing qualifications under both the Chinese National Standard (GB150) and international ASME pressure vessel codes, and leveraging years of experience in executing oil and gas export projects in Central Asia, we custom-tailored this high-capacity, high-efficiency separation unit. The complete system was exported after undergoing rigorous, full-process testing in China, and is now running stably on-site.

Project Overview

Basic Project Information

lProject Location: Uzbekistan

lIndustry: Natural Gas Processing Project

lCore Equipment: Polymer Separator Pressure Vessel (1 Unit)

lEffective Volume: 119.925 m³

lDimensions: 3.9 m × 4.1 m × 7.5 m

lDesign Codes & Standards: Parallel design compliant with GB/T 150 "Pressure Vessels" and ASME Section VIII Division 1.

Key Technical Parameters & Design Standards

Design Codes & Standards

The equipment adopts a dual-standard joint design, simultaneously meeting the requirements of two major regulatory frameworks:

Domestic Standard: Full compliance with the GB/T 150 pressure vessel specifications, meeting Chinese special equipment manufacturing supervision and inspection requirements.

International Standard: ASME Section VIII Div. 1, accommodating third-party inspector (TPI) audits and local equipment registration and licensing for overseas projects.

The complete set of fabrication drawings and testing reports is provided in bilingual English-Chinese formats to streamline reviews by overseas owners and third-party inspection agencies.

Material Selection

To withstand the corrosive and erosive working environment in Uzbekistan—characterized by H₂S and CO₂ acidic gases, solid polymers, and abrasive sand particles—materials were selected with targeted precision:

The shell and head main body utilize specialized H₂S-resistant pressure vessel steel plates to withstand long-term wet H2S corrosion.

The internal components are made of wear-resistant stainless steel to resist continuous erosion by solid particles and reduce the accumulation and scaling rate of polymers.

The exterior is protected by a weather-resistant, anti-corrosion coating system, specifically engineered for open-air outdoor environments featuring large diurnal temperature fluctuations, dry climates, and blowing sand, thereby delaying external rusting and aging.

Working Principle & Internal Structure

The horizontal polymer separator utilizes a three-stage progressive separation structure. Relying on the triple physical mechanisms of centrifugal energy dissipation, gravity settling, and fine coalescing, it removes solid polymers, sand, and liquid-phase impurities (oil and water) from natural gas in a single pass. It serves as the core pressure equipment for primary natural gas purification.

Stage 1: Centrifugal Primary Separation

The pressurized, multi-phase gas-liquid-solid mixture enters the vessel inlet tangentially. As it passes through a specialized inlet vane distributor, its kinetic energy is dissipated, creating a rotational centrifugal force. Solid polymers, sand, and large liquid droplets with higher specific gravity are slung against the vessel wall. Gravity then pulls them down into the bottom liquid storage area of the vessel, achieving over 60% removal of heavy impurities and significantly reducing the load on downstream components.

Stage 2: Gravity Settling Separation

After energy dissipation, the mixed gas enters a spacious settling chamber. Based on Stokes' Law of gravitational settling, the water, condensate oil, and natural gas separate into layers due to their density differences: the heavy water phase continuously sinks, the oil phase remains suspended in the middle layer, and the clean gas phase accumulates at the top. The vessel's volume was calculated through precise computational fluid dynamics (CFD) simulations to ensure sufficient retention time. This allows tiny liquid droplets and polymer particles to fully settle, creating a stable oil-water interface, while internal weirs precisely control the layering height to allow independent oil and water discharge.

Stage 3: Coalescing & Fine Demisting

The rising gas phase passes through a combination of multi-layer coalescing plates and a high-efficiency mist eliminator. As the gas flows through the micro-passages, micron-sized polymer droplets and tiny water mists continuously collide and coalesce, forming larger droplets that fall back into the liquid phase zone. The dry gas emerging from this third stage is virtually free of entrained solid and liquid impurities, drastically reducing clogging and corrosion risks for downstream compressors and pipelines.

Manufacturing & Delivery Highlights

Fabrication & Testing Standards: NDT, Hydrostatic, & Pneumatic Tests

As an exported pressure vessel, every step of fabrication—from steel plate receiving to final product shipment—strictly executed the dual GB and ASME standards without any simplification:

Spectroscopic re-testing of raw materials upon arrival to verify material grades and mechanical properties.

Detailed process records maintained throughout plate rolling, forming, and welding. All welders hold dual qualifications under domestic special equipment and ASME standards.

100% Non-Destructive Testing (NDT) via Radiographic Testing (RT) performed on all pressure-retaining welds by our certified in-house NDT team, enforcing a zero-tolerance policy for defects.

Post-Weld Heat Treatment (PWHT) completed to eliminate residual forming and welding stresses, preventing long-term pressure-induced deformation or cracking.

Sequential hydrostatic strength testing and pneumatic leak testing performed with pressure maintained and monitored to ensure zero leakage and zero pressure drop.

Internal and external sandblasting followed by multi-layer, weather-resistant, anti-rust coatings with thickened paint films to resist Central Asian sandstorms and extreme day-night temperature swings.

A complete set of English-Chinese as-built documentation, NDT reports, pressure test records, and ASME compliance documents compiled and delivered alongside the equipment.

On-Site Installation Guidance & Commissioning Services

We employ professional international technical service engineers who can guide the entire hoisting, piping alignment, pressure testing, and commissioning processes on-site. If requested, technical personnel can be dispatched directly to the project site in Uzbekistan to provide hands-on installation support, quickly resolving interface and commissioning issues to ensure the project begins production on schedule.

Applications & Market Outlook

Applicable Scenarios: Gas Gathering Stations

This polymer separator is widely applicable to onshore gas gathering stations, oil and gas treatment plants, and coalbed methane purification facilities. It is specifically engineered for raw gas conditions containing solid polymers, sand, and acidic corrosive media, delivering highly efficient three-phase separation of gas, oil, water, and solid impurities. This protects downstream compressors, heat exchangers, and transport pipelines while reducing maintenance overhead caused by clogging and corrosion.

In addition to Central Asian gas projects, this equipment is fully adaptable to oil and gas extraction and purification projects in the Middle East, Southeast Asia, South America, and other regions. Dimensions, materials, and internals can be custom-tailored based on local gas compositions, climate conditions, and applicable engineering codes.

Company Capabilities

Shijiazhuang Zhengzhong Technology Co., Ltd. (Center Enamel) is recognized as a national "Specialized, Finessed, Unique, and Innovative" High-Tech "Little Giant" enterprise. We operate a large-scale pressure vessel manufacturing plant equipped with independent welding, heat treatment, and non-destructive testing workshops.

Holding official ASME U-stamp certification, we independently execute custom design, fabrication, testing, and export delivery for polymer separators, oil-gas separators, heat exchangers, reactors, and evaporator packages. We are highly familiar with special equipment import codes across Central Asia, the Middle East, and Southeast Asia. Backed by a strong track record of global oil and gas project deliveries, we provide a one-stop solution for pressure equipment procurement, certification, transportation, and technical coordination.

Secure Your Gas Processing Operations with Center Enamel

In natural gas extraction and purification processes, the polymer separator pressure vessel serves as the critical first barrier safeguarding the operational stability of the entire production line. This is especially true for gas fields in locations like Uzbekistan, where raw gas contains high concentrations of polymers and acidic impurities; here, the equipment design, material selection, and manufacturing quality directly dictate long-term plant operating costs.

The high-capacity horizontal polymer separator delivered for this Uzbekistan project—engineered using dual GB150 and ASME standards, featuring a high-efficiency three-stage separation structure, and crafted with sulfur- and wear-resistant materials—passed all rigorous NDT and pressure testing. It perfectly matches local gas conditions and successfully resolves the client's pain points of frequent clogging, corrosion, and maintenance downtime.

Moving forward, Center Enamel will continue to deepen its presence in the global oil and gas pressure equipment market. Leveraging our extensive overseas project experience and robust manufacturing and testing infrastructure, we deliver highly reliable, compliant, and custom-engineered pressure vessel solutions for natural gas and chemical EPC projects worldwide. Please contact us to discuss your project specifications and obtain a customized engineering proposal.