Gates Product Application on YouTube

Have you had a chance to check out our latest instructional and educational videos on YouTube?  We have recently added several videos including those pertaining to transfer hose, hydraulics, crimping machines, and even hose cutters.  If you have never looked at the Product Application page or simply haven't visited the site in a while, you can do so by following the link below.

www.YouTube.com/GatesPT

For any additional questions feel free to look through our other blog topics or contact us at ptpasupport@gates.com or 303-744-5800.

Gates Pulley Specifications

Detailed drawings and dimensions of Gates pulleys are shown in drive design manuals and online at www.Gates.com/PartView.
It's very important to understand that the details shown which do not affect drive function may be changed without notification. If a specific construction or material is needed for your pulley then it must get sourced through our Made to Order Metals department.

Minimum Belt Wrap and Tooth Engagement

Did you know that synchronous belts need a minimum amount of wrap along with a minimum amount of teeth in mesh to transmit rated loads?  The minimum teeth required in mesh to achieve rated drive capacity is 6 teeth.  Anything less than 6 teeth reduces rated capacity significantly.  In fact, for each tooth less than 6, you lose 20% of the rated load!  This means at 4 teeth, you’re already down 40% of the rated load capacity!  And as mentioned above, this isn’t the whole story.  Even if you have 6 teeth in mesh, but you have less than 60 degrees of wrap, you may have belt problems.  This really only applies to drives with more than two shafts.  Idlers that do not transmit load do not have a minimum tooth engagement or degree of wrap required.

Industrial Hose Service Life

All rubber products, including Industrial hose assemblies, have a limited life on a given application. Assuming the correct hose has been selected for the application, this service life can be adversely affected by many variable conditions. The major ones are:

o   Exposure to severe external abuse such as kinking, bending, high end pull, crushing or abrasion

o   Exposure to higher than rated working pressures or  to high surge pressures

o   Exposure to higher than rated temperatures

o   Misapplications or exposure to corrosive liquids or gases outside the range of suitable applications.

External abuse – hoses should be placed where they will not be run over by equipment or subjected to high end pull. Hoses should not be bent below recommended minimum bend radius. This could result in kinking the hose or reducing its pressure resistance. Large diameter hoses also may require additional support to reduce the external abuse

Hose and system pressures – In establishing and determining pressures related to hose and the systems to which they are applied, it is necessary to consider separately the characteristics of the hose and the system.

o   The system (or device or applications) can have several pressures depending on pressure sources and surges imposed by the operator or mechanical components.

o   A given hose has a fixed characteristic with respect to the pressure it can withstand (and how it is applied) and still give satisfactory life

High Temperatures - The allowable temperature ranges for industrial hoses are shown on the High Temperature Ranges page. These are for product temperatures and should not be exceeded. High temperatures can degrade rubber stocks very quickly resulting in short service life. Where external temperature are higher than normal ambient, contact your Gates field representative for recommendations.

Misapplications – All industrial hoses are designed for certain specific application or related application. They should not be used for any other applications.

Hose Information – Refer to the Gates Industrial Hose Catalog for detail of hose constructions and physical characteristics. These are shown in the data pages and include such items as rated working pressure, vacuum rating, maximum bend radius, and static conductivity.

Internal Abrasion – For applications of a highly abrasive nature where the hose makes one or more bends, the hose should be rotated 90 degrees periodically to lengthen service life.

The hose manufacturer established, through design and testing, the recommended rated working pressure for the hose. It is the responsibility of the user to accurately determine the system pressure. Steady state pressure can be measured readily by gauges. Surges are difficult to measure and may require the use of electronic pressure pickup devices. Also, surge values depend on so many variables that a series of tests are usually required to obtain a valid set of readings. However, if there are extreme surges in the normal operation or if there is the likelihood of abnormal operation of the system, the magnitude must be determined.

Considering the recommended rated working pressure of the HOSE and the various pressures of the SYSTEM, the hose is matched to the system using proper application engineering principles. End terminations may reduce the rated working pressure of hose assemblies. Refer to coupling manufacturer for recommendations.

Temperature - Safe Hose Selection

An effective way to remember this hose selection criterion is to

remember the word STAMPED.

S = Size

T = Temperature

A = Application

M = Material to be Conveyed

P = Pressure

E = Ends or couplings

D = Delivery (volume)

Temperature (T)

When selecting a replacement assembly, two areas of temperature must be considered. These are fluid temperature and ambient temperature. The hose selected must be capable of withstanding the minimum and maximum temperature of the system. Care must be taken when routing hose near hot manifolds, and in extreme cases, a heat shield may be advisable.

Actual service life at temperatures approaching the recommended

limit will depend on the particular application and the fluid being used in the hose. Intermittent (up to 10 percent of operating time) refers to momentary temperature surges. Detrimental effects increase with increased exposure to elevated temperatures.