Tag Archives: mechanical seal

Compressor Seals: The Espey™ WKA250ND

Espey chamber seals have a modular design which means the seals can be composed using standard parts to meet individual application requirements. Espey chamber seals work with a very small operation gap between shaft and seal ring – leading to very low leakage – and are designed for dry-running and compensate radial and axial shaft deflections. Another advantage is that no sealing components which could generate additional shaft vibrations are actually fitted on the shaft. The seal rings are axially spring-loaded to prevent swinging up at pressure-less machine operation.

Espey chamber seals are applied in several turbo machines: integral gear, screw and chiller compressors, steam turbines, and shut-off valves for power plants. The main industries in which it is implemented are oil and gas, refining, chemical and petrochemical industry, power plants, and plants for iron and steel production. A further industry field with several references and successes is carbon dioxide capture and storage (CCS). So, what might a success story look like? Check out this WKA 802 HD mechanical seal for a multi-stage integral-gear compressor:

Espey Application Story

Espey™ WKA 802 HD as sealing for a multi-stage integral-gear compressor in a fertilizer production facility.

Client’s Issue

Urea is the worldwide leader in nitrogen fertilizer production. Urea is produced via high pressure synthesis from liquid ammonia and a gas-water mixture with 88.7 % carbon dioxide under high pressure and elevated temperatures in a synthesis tower. Thereby synthetic ammonia carbamate is produced, which is finally obtained as white granules under supply of acid and heat. The high pressure processes are generated by multi-stage radial integrally geared compressors. The seal has to work as leakage protection of the highly-compressed CO2.

The Espey Solution

turbo compressorEspey developed the compact chamber seal Espey™ WKA 802 HD with barrier gas and leakage port and up to 8 seal rings for this radial integrally geared compressor (which was designed by MAN Diesel & Turbo SE). The operation pressure of 140 bar (2031 PSI), the temperature of 225 °C (437 °F) and revolutions up to 40,000 min-1 were the main design parameters. Each of the 8 stages was equipped with an individual Espey ™ WKA 802 HD with different installation lengths, seal, and outer diameters. The one-piece seal rings with titanium bandage were designed axially spring-loaded to avoid vibrations during start and spin-out phase.

The Espey Result

The seal solution has been highly reliable and routinely operates maintenance-free, helping to maximize production.

About the Shaft Seal Espey™ WKA250ND – 1100HP

picture of WKA250NDFeatures
  • Chamber seal (modular design), optional with housing and lidVery small operation gap – low leakage
  • Dry running
  • Compensation of radial and axial shaft deflections
  • No sealing components mounted on the shaft and hence no additional shaft vibrations
  • Seal rings running contact-free – sliding faces and machine consume no additional power
  • One-piece seal ring with titanium bandage
  • Both side balanced seal ring inside chamber for short-term back pressure operation
  • Seal ring axially spring-loaded – no swinging up at pressure-less machine operation
Advantages
  • High reliability
  • Maintainability
  • Maintenance-free
Recommended Applications
  • Gases
  • Fumes and exhaust, solids containing, flammable
    (ATEX), acid containing and toxic gases
  • (Solids containing) steams/liquid mist
  • Oil mist/penetrating oil
  • Water
  • Oil and gas industry
  • Refining technology
  • Chemical and petrochemical industry
  • Pulp and paper industry
  • Metal production and processing
  • Power plant technology
  • Integral-gear compressors (one or multi-stage)
  • Screw and chiller compressors

For more information about mechanical seals, contact Gallagher Fluid Seals today. Gallagher is a preferred distributor for EagleBurgmann mechanical seals.

The original case study and materials for Espey WKA 802 HD can be found on EagleBurgmann’s website.

The Complete Guide for Mechanical Seals & API 682 4th Edition Piping Plans

Mechanical Seals & API 682 4th Edition

A sealing system, consisting of a mechanical seal and an associated supply system that is balanced by individual applications, is the utmost guarantee for a reliable sealing point and uninterrupted pump service. The performance of the seal is greatly influenced by the environment around the seal faces, making the provision of suitable, clean fluids as well as a moderate temperature an essential topic.

This guiding booklet provides a condensed overview of all piping plans established by the API 682 4th edition guidelines. Each illustrated piping plan is briefly described, and a recommendation that considers the media characteristics in terms of the relevant application and corresponding configurations is given to help you reliably select your sealing system. Furthermore, the content of this booklet has been enriched by providing clues – so-called ‘remarks and checkpoints’ – where EagleBurgmann shares the experiences gained from multiple equipped plants.

Sealing solutions to meet any requirement

Several factors play a major role when choosing the product, the product type, the materials used and how it is operated: process conditions at the sealing location, operating conditions and the medium to be sealed.

No matter what requirements our customers have, EagleBurgmann understands how these factors affect functionality and economic viability, and they translate this expertise into outstanding long-term, reliable sealing solutions. EagleBurgmann has all the expertise needed to manage and support the entire development, life and service cycle of its sealing solutions.

Plan 75 Piping Plan Example

EagleBurgmann and API 682

EagleBurgmann offers customers the widest product portfolio of seals and seal supply systems according to API 682 4th edition. The configurations listed for each individual piping plan are to be understood as recommendations including possible utilizations which may also be applied.

EagleBurgmann Profile

EagleBurgmann is one of the internationally leading companies for industrial sealing technology. Their products are used wherever safety and reliability are important: in the oil and gas industry, refining technology, the petrochemical, chemical and pharmaceutical industries, food processing, power, water, mining, pulp & paper and many others. More than 6,000 employees contribute their ideas, solutions and commitment towards ensuring that customers all over the world can rely on their seals and services. More than 21,000 EagleBurgmann API-seals and systems are installed world-wide.

Case Study: A Single Mechanical Seal, But Twice As Safe Under High Pressure

Mechanical Seal SHVI and Plan 66A for Unmanned Pump Station of an Oil Pipeline

A well-known Canadian operator of an oil pipeline commissioned EagleBurgmann to develop a sealing solution for crude oil pumps. The requirement: It needed to be a single seal that was just as safe as a double seal with buffer pressure system. In addition, the sealing solution was not to be designed for only one pump type but should be installed in various pumps of one station.

SHVI Operating Conditions

The operating parameters were quite extensive: The seal needed to be suitable for a pressure range from 2.5 bar (36 PSI) to 99 bar (1,436 PSI) as well as for shaft diameters from 115 mm to 155 mm (4.53’’ to 6.10’’). Since the pump stations are operated unmanned, the seal must operate without an additional supply system. To protect the environment and personnel, however, the seal housing must not leak if the seal fails unexpectedly.

The solution: Mechanical seal SHVI from EagleBurgmann

These requirements were best met by the SHV series which has proven itself thousands of times over in crude oil pumps and MOL pumps (MOL: Main Oil Line) of all types worldwide for many years. For the Canadian customer, EagleBurgmann developed the SHVI sealing variant with loosely inserted seal face specifically for the high-pressure range. The seal face is single, but is twice as safe under high pressure and is designed such that it always builds a parallel sealing gap with the stationary seat. The deformation behavior of the seal  face was optimized for use in crude oil pumps so that the seal operates reliably even under very high pressures, sliding velocities and temperatures as well as pressure and temperature fluctuations.

Silicon CarbideEagleBurgmann selected a special quality of the silicon carbide material to be used in the pumps of the pipeline operator. This provides the seal face with particularly good emergency running properties and tolerance for partial dry running. In addition, the sliding faces have extremely precisely ground grooves which allow the seal face to be lifted quickly even in the low pressure range and contribute to stable operation in a wide pressure range.

Safety: Optimized API Plan 66A

Plan 66A, which has been available since introduction of API 682 4th Edition, was the obvious choice for the safety concept. Accordingly, the seal housing contains two throttles, and the seal chamber is connected to a pressure transmitter.

SHVI PipelineEagleBurgmann optimized the plan and uses a special inner, floating  throttle. This can withstand a product pressure of 99 bar (1,440 PSI) in an emergency. The pressure transmitter detects pressure changes in the seal chamber and signals an alarm if certain values are exceeded. At the same time, the seal leakage accumulated under low pressure is discharged to a central collection system in the pump station.

Test and Acceptance

The SHVI seal and the optimized Plan 66A were subjected to dynamic and static tests individually and together on EagleBurgmann test benches. The constant and reliable sealing performance in all operating states and the safe function of Plan 66A in the event of a fault provided impressive results. The required system safety was provided at all times.

The new concept of the SHVI single seal with optimized Plan 66A is economical, modular, reliable in operation, and offers the safety of a double seal.

There are plans to convert further pumps of the pipeline operator. The new concept of the SHVI single seal with optimized Plan 66A is economical, modular, reliable in operation and offers the safety of a double seal. For other customers as well, this type of seal has since proven itself in MOL pumps for several thousand operating hours.


To Learn More about the SHV series of mechanical seals, contact us today at 1-800-822-4063 or click the button below.

Contact Gallagher

H75VN Mechanical Seal for Cumene Pump Station

Retrofitting a Pump with an EagleBurgmann H75VN

Cumene, the common name for isopropylbenzene, is an aromatic hydrocarbon and a colorless liquid under atmospheric conditions with a characteristic smell. It is a component of crude oil and refined fuels and is mainly used in the production of phenol.

The Problem

Ineos in Gladbeck and Degussa in Marl, both located in Germany, are supplied with cumene by a pipeline. The pump station for this pipeline is situated inside the chemical industry park in Marl and is operated by Degussa Infracor. Cumene is classified as hazardous to the environment, so the “TA-Luft” directive (German Clean Air Directive) has to be considered for any sealing solution.

Originally, the pump was equipped with a Flowserve mechanical seal type EUROPAC 613/663 in tandem arrangement. With this seal, the required maximum temperature of the supply medium of 104˚F (40°C) was always exceeded and the seal was continuously squeaking during operation.

Operating Conditions

  • Medium: Cumene
  • Operating temperature: 41˚F – 122˚F (5 – 50˚C)
  • Operating pressure at seal: 17.4 – 34.8 psi (1.2 – 2.4 barg)
  • Pump: Centrifugal pump, type MC 80-260/62
  • Pump manufacturer: Sulzer
  • Speed: 2,975 rpm
  • Seals include materials: H75VN/80-FTA5, AQ1KMG – AQ1KMG
  • Mode of operation: Plan 11 and Plan 52 according to API 682
  • Supply system: TS 2000/M051-A1, operation under atmospheric pressure

The EagleBurgmann Solutionpicture of the H75VN

The critical points of this application are the poor lubrication properties and the low heat capacity of the process medium. The engineered EagleBurgmann H75N mechanical dual seal in tandem arrangement was selected and retrofitted to the pump.

Technical features of the EagleBurgmann H75VN seal:

  • Cartridge unit, easy to install
  • Certified according to API 682/ISO 21049 for the application in flashing hydrocarbons. Meets the requirements for low emission seals based on STLE-limit values
  • Counter-rotating pumping screw to support the circulation of the buffer medium to ensure an optimal cooling and lubrication of the mechanical seal
  • Plan 11 and 52 with multi-point injection: the buffer medium is divided into several sub-currents that are directed towards the sliding face at relatively high flow velocities, improving heat removal from the mechanical seal
  • Self-closing: the seal will remain closed and will keep the full functionality even in situations of pressure reversal or failure of the supply system
  • Perfluoroelastomers due to the chemical resistance

Conclusion

The EagleBurgmann H75VN meets all requirements of the operator regarding the maximum buffer fluid temperature of 104˚F (40°C), and the squeaking of the seal was eliminated. The mechanical seals have been successfully in operation since the beginning of 2006 and have been running to the full satisfaction of the customer, with further pumps retrofitted currently. Additionally, the EagleBurgmann H75VN mechanical seal is now specified as standard for pipeline pumps.


Gallagher Fluid Seals is an exclusive distributor of EagleBurgmann. For more information about custom solutions or mechanical seals, contact our engineering department, or call 800-822-4063.