Pioneer Weston Dynamic Metal Face Seals Contact At Pioneer Weston our goal is to deliver a world class service in every area of our operations. Pioneer Weston 206 Cavendish Place, Birchwood Park, Warrington, Cheshire. WA3 6WU Tel +44 (0)1925 853000 Fax +44 (0)1925 853030 email [email protected]Web www.pioneerweston.com An Company
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Pioneer WestonDynamic Metal Face Seals
Contact
At Pioneer Weston our goal is to deliver a world class service in every area of our operations.
Pioneer Weston206 Cavendish Place,Birchwood Park, Warrington, Cheshire.WA3 6WU
Tel +44 (0)1925 853000Fax +44 (0)1925 853030email [email protected] www.pioneerweston.com
An Company
Pioneer WestonDynamic Metal Face Seals
Company Overview
Pioneer Weston has been at the forefront of sealing technology for over 60 years and enjoys an enviable reputation with blue chip OEM’s. We work in close partnership with our customers to innovate, design and manufacture bespoke solutions to suit a diverse range of applications, no matter how arduous the environment. We are proud to hold ISO9001:2008 quality accreditation for dynamic sealing solutions and specialist products.
We continue to invest heavily in our research and development facility forging partnerships with both materials suppliers and academia to expand the boundaries of what is possible with technical sealing solutions, which in turn ensures Pioneer Weston always delivers unrivalled product performance and value to all of our customers.
Quality
At Pioneer Weston we are quite rightly proud of our high quality standards.
Quality is at the core of everything we do; in process, our people and our product. All our employees take personal responsibility for the quality in their sphere of activity and with a ‘Right First Time’ culture - essential in any Total Quality Management operation.
Whether the requirement is for small batch samples for test and validation or volume production, Pioneer Weston’s quality systems ensure that each product meets the highest quality standards.
As the preferred sealing partner of many global manufacturing companies, we have an unrivalled insight into the quality standards that need to be attained.
Metal Face Seals
Metal face seals offer bearing protection and lubricant retention on any relatively slow moving rotary shaft, predominantly found in tracked vehicles such as earth movers, mobile cranes and large off-highway vehicles. The new range from Pioneer Weston is designed at our dedicated UK sealing technology centre in Warrington,and assembled in the UK. Products from this range canbe adapted and re-engineered to match virtually any custom application.
Pioneer Weston’s range of seals excel under extreme environments in severe service applications, where the exclusion of contaminants such as sand, rock, mud and water is of vital importance to the protection of your equipment. Therefore providing a robust, efficient solution with long service life and low maintenance. Typical examples of these heavy duty applications include; construction, mining and tracked agricultural equipment, in fact virtually all tracked vehicles rely on these robust seals.
Sales and technical support is available globally via our own technical specialists, the ERIKS service centre network and via other leading international distributors and technical partners.
Many manufacturers have discovered the benefits offered by Pioneer Weston’s range of metal face seals, with reliable supply, consistently high quality and competitive pricing, everybody wins.
There are two common types of metal face seals on the market, the most popular form is the 5000 Series which is more compact while the 5500 Series offers a slight pressure advantage.
5000 Series
The 5000 Series provides a more compact, cost effective sealing solution, but requires precise machining of the housing bore. The secondary sealing element in this series is characterised with the use of an O Ring, and effectively excludes,sand,dirtandwater,andiswidelyusedinbulldozerand excavator undercarriage applications.
5500 Series
This seal allows for simpler housing design and construction, the housing is easier to machine but more housing space is requiredandfewertooledsizesareavailable.Thesecondarysealing element is of a special washer design instead of an O Ring, which also allows a higher pressure capability. The design provides an ideal solution for agricultural equipment and other field machinery.
Interchangability and Availability
Our range of metal faced seals includes all the popular sizesusedtodaysoreplacementpartsareavailableforwhen you upgrade to Pioneer Weston and no matter where you manufacture, we can supply you direct or via our Authorised Distributor.
Method of Operation
The O Ring and the elastomeric washer provide three different functions:
• Theyprovideuniformaxialpressureforthemetallicsealing surfaces to mate effectively whilst self centering the rings. • Theyactasastaticsealattheinnerdiameteragainstthe sealing ring and outer diameter against the housing bore.• Theytransmitthetorquefromtherotatinghalfofthe housing through the faces to the static half and prevent the metal ring from turning with the shaft.
The metallic seal surfaces are produced by an automated extremely accurate grinding and lapping process, one of the rings rotates against the other at a right angle to the shaft to provide a leak proof seal.
The rings are designed in such a way that they open out from the lapped faces towards the shaft giving a wedge shape gap. This enables easy lubrication to the faces by capillary action and centrifugal force. Lubrication is essential to the life of the seal it keeps running temperatures down and keeps the faces from cold welding together.
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Seal Types
Selection and Material Specification
Ensuring the correct material composition is paramount to successful performance, Pioneer Weston can work with you to analyse your requirement and recommend the most suitable seal to fit your design criteria even helping your engineers to design the installation and provide electronic drawings to speed up the process.
Below are the main factors in ensuring the correct selection, the most critical being the correct metal or seal ring material.
• Size• Temperature• Speed• Pressure• Media
C – Corrosion Resistant Cast Iron
This is the most widely used seal face material and is a high alloy, corrosion resistant cast iron with a natural hardness of 58HRC,aftercastingitisincreasedto65-72HRCbyheattreatment. These castings are then processed by grinding, lapping and polishing. Maximum operating parameters are 2 bar pressure and 3m/s circumferential speed when lubricated.
F – Forged Roller Bearing Steel
A cheaper alternative to cast iron. Seals made from this material are manufactured by copy turning followed by an induction hardening. After the hardening process the faces willbe>58HRC.Maximumoperatingparametersfortheseseals are 1.5 bar pressure and 2 m/s circumferential speed when lubricated.
X – Casting Alloy
Developed for the most X-treme applications where high abrasion resistance is necessary to prevent high speed scoring of the faces. Maximum operating parameters for these seals are 2 – 2.5 bar pressure and 3-4 m/s circumferential speed when lubricated. This material is widely used in Mining, Bulldozerandexcavatorapplications.
Steel Composition and Selection
X C F
Process Cast Cast Forged
Cost High Medium Low
Wear Life High Medium/High Low
Corrosion Resistance High Low/Medium Low
Abrasion Resistance High Medium/High Medium
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Typical Seal Reference:
AM5084-C-NB60
Sizeref. Metal Ring
Elastomer
Hardness
Selecting the correct material for the O-ring or washer is equally if not more important than the correct metallic face. As part of the ERIKS group (acknowledged as the largest manufacturer and supplier of O-rings throughout Europe) you can be sure Pioneer Weston metal face seals have the compound to meet your requirements.
The 4 most common elastomer types for this family of seals are;
Nitrile (NB)
Chemically, is a copolymer of butadiene and acrylonitrile. Due to its excellent resistance to petroleum products, relative low cost and its ability to be compounded for service over a temperaturerangeof-35°Cto+120°C,Nitrileisthemost widely used elastomer in the seal industry today.
Hydrogenated Nitrile (HN)
Was developed to meet higher temperatures than standardNBwhileretainingresistancetopetroleumbasedoils.HNisresistanttomineraloil-basedhydraulicfluids,animalandvegetablefats,dieselfuel,ozone,sourgas,diluteacidsandbases.HNalsoresistsnewbio-oils(biologicaloils).HNissuitableforhighdynamicloadsandhasagoodabrasion resistance.
HNissuitablefortemperaturesfrom-30°Cto+150°C.
Silicone (VMQ)
Silicones are a group of elastomeric materials made from silicone, oxygen, hydrogen, and carbon. Extreme temperature rangeandlowtemperatureflexibilityarecharacteristicsofsilicone compounds. Silicones possess excellent resistance toextremetemperatures-50°Cto+232°Calthoughasagroup have poor tensile strength, tear resistance and abrasion resistance.
Fluorocarbon (FKM)
Fluorocarbonelastomersarehighlyfluorinatedcarbon-basedpolymers used in applications to resist harsh chemical and ozoneattack.Theworkingtemperaturerangeisconsideredtobe-26°Cto+205°CButforshortworkingperiodsitwilltake even higher temperatures. Fluorocarbon elastomershave grown to major importance in the seal industry due toits wide range of chemical compatibility, temperature range, low compression set, and excellent aging characteristics.
If needed we can develop a special compound to meet specific requirements or choose from over 500 compounds already developed. For more information such as datasheets please visit www.o-ring.info
NB HN VMQ FKM
LowTempRange°C -35 -30 -50 -26
HighTempRange°C 120 150 232 205
Abrasion Resitance Excellent Excellent Poor Good
Oil Resistance Excellent Excellent Poor Excellent
Tear Resistance Good Good Poor Good
Water Resistance Excellent Excellent Excellent Fair
Cost Low Medium/High Medium High
Load Ring Materials
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Installation and Maintenance
Pioneer Weston metal faced seals can easily provide over 3000 hours of maintenance free performance without the need for oil replenishment however correct installation of the seal is critical to this long service life.
Installation Method
1. Ensure that the inside of the housing is clean, free of burrs, scratches and dust. The load ring must be correctly fitted on the seal and be free from distortion (see Figure A).
2. Install the seal with load ring in the housing (Figure B). At this time, confirm that the end of the housing (1) will be parallel to the lapped surface of the seal (2). If the seal becomes out of alignment, even partially (Figure C) the seal shall have abnormal wear the o-ring will become distorted and will eventually fail prematurely.
3. After insertion, make sure that the precision lapped surfaces are absolutely free of foreign matter, then lightly apply lubricant oil to the mating surfaces. Upon completion of the seal installation, reassemble the housings to the correct setting gap (see below) and fill with lubricating oil.
When properly installed, the two mated metal surfaces seal against each other, a thin film of lubrication between these two surfaces minimises wear, and the load rings provide pressure to ensure positive sealing.
Setting gap
The setting gap (A) determines the amount of axial pressure on the sealing faces and the compression applied to the elastomeric rings. Pioneer Weston seals are designed so a setting gap (A) of 3+/-0.5mm will provide adequate sealing force forthemajorityofapplications.Howeverifthesealsarerequiredto work at a continuous high peripheral speed the setting gap should be adjusted in order to prevent an excessive loading of the lubricating oil.
This will reduce surface pressures and can be done by increasing the setting gap (A) .In this case tests should be conducted to find the most suitable setting. Lubrication
Correct installation will count for very little if the lubrication regime is overlooked or incorrectly administered. The seals will have a far greater operating life when provided with good lubricating and heat dissipating qualities when oil is used as opposed to grease.
Oil
Transmission oils, grade SAE 80 and SAE 90 are recommended. If necessary, lower viscosity lubricants such as engine oil 20W 20canalsobeused.Incaseswherehydraulicfluids/Bio-oilsare to be used, please contact Pioneer Weston direct for advice.The oil level should be between the axis centre line and 2/3 of the seal diameter. When filled to the correct level, the oil will generally suffice for the lifetime of the seal.
Grease
Although grease can be used as a lubricator it is not recommended due to the fact it will not centrifuge to the wedge gaps in the seal faces during dynamic conditions. If grease is used it will result in higher wear, shorter lifetime and can only run at slower sliding speeds.
The seal should, on no account, be regreased with a grease gun, as the high pressure of the gun can dislodge the o rings and ultimately destroy them.
Figure A Figure B Figure C
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1
2
1
2
Part No. Seal Set O-Ring Housing Dimensions
A +/-0.5
ØDi ØD0 H ØID CS ØD1* ØD2* ØD3* ØD4 H1 H2 min H3 H4 R +/- Tol for *