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Filtration solutions for Dry Seal Gas

Dry Gas Seals (DGS) task

Within the gas lubricated shaft seals, dry gas seals (DGS) are the most common type of seals used in the Oil & Gas industry. The Dry Gas Seal outperforms other types of seals for demanding applications and are specified by standards like the API 692. Its main task is to prevent uncontrolled escape of process gas from a compressor to the atmosphere and to avoid contamination to, or from the lubrication system.

Dry Gas sealing systems are used for axial, centrifugal, rotary screw compressors and expanders throughout the industry.

The dry gas seal has a rotating mating ring and a stationary primary ring. When the mating ring rotates, the grooves in the mating ring create a dynamic pressure, which forms a running gap between the 2 faces. This running gap receives the clean seal gas, which acts as a barrier between the atmospheric gas/air and the process gas. The gap varies in a range of only a few microns, and therefore requires a high quality of the supplied gas.

Using a clean seal gas is essential to avoid the damaging of seal faces, which can lead to contamination and loss of process gas.

Seal gas conditioning with BOLLFILTER seal gas filtration solutions

BOLLFILTER Seal Gas Filters and Separators provide clean seal gas by removing dirt and moisture form the gas supplied to the Dry Gas Seal. Particles and aerosols are removed with an efficiency of up to 99,99% down to particle and droplet sizes of 0,1 µm.

The Dry Gas Supply Skid is the driver of the quality of gas delivered to the Dry Gas Seal through the regulation of pressure, temperature, flow, and gas cleanliness.

Dry Gas Seal systems are typically differentiated by 3 classifications depending on the application – Primary, intermediate, and secondary supply lines.

Primary seal gas supply line

This is commonly the first stage starting from the process side of the compressor. It uses process gas which is conditioned to be able to be handled by the DGS. Depending on the contamination levels in the process gas, different arrangements for the conditioning might be required. When high loads of aerosols, moisture or particles are expected, a pre-separator becomes indispensable.

The pre-separator is commonly a cyclone, buffer plate or demisting separator, or in some cases a combination of these.

The primary seal gas filter is commonly a coalescing filter unless it is guaranteed that the gas is 100% free of moisture or liquid contaminants. This might be the case for example in some cryogenic applications.
In general, if the knockout rates exceed 50 % of the coalescing capacity of the element, it is suggested to install a mechanical separator ahead of the filter assembly.

Intermediate treated gas supply line

The intermediate seal gas supply line is commonly only present in high pressure arrangements or when handling harmful gas. It presents an intermediate stage between the primary and the secondary seal gas for added safety. Commonly used non harmful gases in this application are air or nitrogen.

Secondary treated gas supply line

The secondary seal gas supply line is present in most applications within the Oil & Gas industry. It serves to prevent contamination into the DGS, as well as providing the “outer barrierof the gas seal to the environment, ensuring that any leakage from the primary or intermediate seal gas is vented to the flare. Like the intermediate supply, non-hazardous gases such as air or nitrogen are the most commonly used.

BOLL & KIRCH experience in seal gas filtration

With more than 20 years of experience and engineering practice in the field of Dry Gas Seal applications, BOLL & KIRCH is the globally recognized, premier partner to solve your filtration needs.     

BOLL & KIRCH is a world renowned, leading supplier of seal gas filters and various separation solutions that fulfill the highest requirements and standards for DGS gas supply systems.

We offer dedicated solutions for upstream, downstream and midstream applications.
Starting from basic onshore gas compressors to the most demanding offshore high-pressure injection compressors, BOLLFILTER covers the complete range of customized filters and separators for the conditioning of the gas supplied to the Dry Gas Seal.

Our trusted and field-proven products provide optimal protection of expensive, process critical equipment for the Oil & Gas, chemical, and power generation industry for low, mid and high-pressure applications.

Your benefits:

  • Wide range of products from standard designs up to the most demanding customized executions
  • Compliance with all international & national standards (e.g. ASME Standards, AD2000, EAC, DOSH, PED, API 614, API 692, NACE, etc.)
  • Providing optimal safety to the operating staff by manufacturing to the most demanding EHS regulations
  • Compliance to specific operator requirements and standards (e.g. SHELL DEP’s, STATOIL TR’s)
  • Extensive in-house testing equipment to continuously develop and improve the performance of our products
  • In-house manufacturing and development of filter elements. 
  • Protection of expensive, process critical equipment for the Oil & Gas, chemical, and power generation industry for low, mid and high-pressure applications
  • Ensuring high availability and productivity of equipment by reducing downtime due to maintenance

Reference

Preview Image: MAN Turbo AG

MAN Turbo AG »

When it comes to the operating safety of its plant and machine units, MAN Turbo AG, one of the world‘s leading manufacturers of turbo machineries, relies on BOLLFILTER.
 

 

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For each type of gas, volume of gas, required degree of purity, type of plant & all operating conditions, BOLLFILTER offers a perfect gas filter ▶ Read more!
Industrial Gas Filtration

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