Answer:
The correct fit of the Universal Sure-Seal Clamp is important in order to maintain the integrity of the seal in each application. While each size clamp has a generous range of fit, it is important that the clamp size chosen fits comfortably in the size range of the components to be clamped.
In determining the clamp size to be used, first determine the actual outside diameter (O. D.) of the component onto which the clamp will be installed. Choose the clamp size that is closest to that outside diameter.
The stock size clamps shown in the catalog have been chosen to fit a wide variety of applications. All sizes noted are with the clamp in the open position, also clamp part numbers also denote the clamp size.
In exhaust applications using rigid steel or flexible tubing, such as that used for heavy-duty trucks, off-road equipment and automotive, the clamp size to be used should be .280" over the size of the tubes to be clamped, i.e. if a vehicle has a 3.0" exhaust system, the clamp size to use would be 3.280" I.D. (inside diameter of the clamp in the static/open position) Ottawa P/N SSC3280. The reason for this size selection is to allow the clamp to fit over a flexible metal hose to rigid tube application, if needed, but also to seal a rigid tube to rigid tube application where one section of the tube has been expanded or swaged to fit over the other tube (usually the O. D. of this expansion is .170" over the nominal O. D. of the tube). By utilizing a clamp size with .280" over the nominal size of the tube, the clamp will torque down snugly to produce a secure and sure-seal in both applications.
The proper size clamps for rubber hose applications are generally chosen based on the O. D. of the rubber hose. Sure-Seal clamps are produced in a wide variety of sizes to accommodate most popular size rubber hose.
In general, it is important to use the size clamp that comes closest to the nominal O. D. (outside diameter) of the components to be joined. If you are still in doubt about which size clamp should be used for a particular application, please contact the factory.
While we try to build a clamp to fit every application and size, we know that there may be a size that will not fit into our stock size range; therefore, special/custom size clamps can also be ordered usually without a tooling charge. Please contact the factory for more information.