Having Trouble Finding the Correct Seal?

REMEMBER TO S.T.A.M.P. BEFORE YOU SEAL!!

            Think of the procedure you follow when attempting to order a sealing solution for a particular application.  Have your hands automatically started to gravitate towards your head, searching for the clumps of hair to begin tugging at?  Taking it a step further, does your company even have a procedure in place for you to follow?  Often times the answer is a resounding "No!" and this most often leads to spikes in blood pressure as well as unique hair-loss patterns.  Fortunately
for you, these times of stress and confusion have come to an end thanks to S.T.A.M.P.!  This guideline has been established and provides five specific criteria regarding your sealing solution and its’ application.

S.T.A.M.P.

• Speed - What is the speed under which the seal will be required to perform?  This speed could be represented as RPM (Rotations Per Minute), FPM (Feet Per Minute), or MPS (Meters Per Second).
• Temperature - What are the minimum and maximum temperatures the seal will be exposed to in the application?  This could be given by degrees in either Celsius or Fahrenheit. 
• Application - Where is the seal being used?  What is the seal function?  This refers to the equipment in which the seal is being installed as well as what the function is of the seal in the application.
• Medium - What is the media?  This is referring to the lubricant or viscous material that is to be sealed or excluded.  Are there compatibility considerations?  Examples of possible media are grease, oil, hydraulic fluid, water, etc.
• Pressure - What are the minimum and maximum pressures the seal will be exposed to in the application or environment?  This could be designated in either PSI (Pounds per square inch) or BARS (1 BAR is equal to roughly 14.5 psi).

After you have determined the S.T.A.M.P. criteria, the next step is determining the dimensions for your seal.  These values could be given in two different methods; either the actual SEAL dimensions OR the STEEL dimensions, i.e. the shaft, bore and groove dimensions.  The vast majority of seal suppliers prefer that the dimensions provided are the steel dimensions, since it is sometimes difficult to measure the actual seal inner diameter.  For replacement seals, the steel dimensions are usually found on the rubber outer case portion of the seal.  There are three key measurements that must be described:

• Inner Diameter – This is the shaft diameter.
• Outer Diameter - This is the diameter of the bore.
• Width - This is the groove height.

Once your seal supplier has this S.T.A.M.P. information, an appropriate style of seal must be determined.  There are many styles of seals to choose from depending on the application, however, there are six standard style profiles for seals.  They are normally designated by their ISO descriptions: A, AS, B, BS, C and CS.  For additional information on these standard styles, as well as other styles, please refer to the Colonial Seal Co. profile chart.

The final step in the designing phase of your seal selection is to determine which case/spring and lip materials are suitable for your application.  What type of steel is to be used in the seal outer case, inner case, and (if applicable) the spring?  Does the application dictate an all rubber covered seal or a metal-cased seal?  What is the lip material required for your application?  Depending on compatibility, these materials range from standard NBR (Nitrile Butadiene Rubber) to high performance materials such as Viton, Teflon, Silicone, and Urethane.

            With the S.T.A.M.P. guideline answers, feel free to breathe a sigh of relief the next time you are assigned the task of finding a particular sealing solution.  Whether the seal is an industry standard part or a custom design for your unique application, rest assured that you will be able to provide the proper solution thanks to S.T.A.M.P.!  For any additional information or to request a quote please visit our website at www.colonialseal.com/contactus.html.