Manufacturers Crimp Guidelines Sure Seal Crevice Free Hose Couplings Caution Sure Seal Crevice Free Hose Couplings are to be used on rubber food hose approved by Key Industrial, Napa, CA. They are intended for use with specific types of hose manufactured for the food and beverage industry. They are not to be used with plastic or other unapproved hose. These are unique sanitary couplings that have been tested for their intended use only. All installers of Sure Seal Crevice Free Hose Couplings must be approved and authorized by Key Industrial, Napa, CA. Sure Seal Crevice Free Hose Couplings Crimp Guidelines are provided specifically for 1) Meeting 3-A/USDA sanitary criteria for hose assemblies. 2) To provide secure hose barb retention. Important These guidelines are more extensive than most. They are intended to enable our distributors to meet 3-A requirements for a sanitary hose to hose barb junction point as stated in 3-A Sanitary Standards for Hose Assemblies Number T-62-02 shown here: The compression required to create the 360 seal defined in C4.1.1and C4.1.2 for Type 1 and Type 2 Sanitary Hose Couplings creates a slight bulge near the interior junction of the hose and coupling in assemblies utilizing hoses made of rubber or rubber-like materials. This bulge indicates compression of the hose material as necessary to create a 360 seal. This bulge may be visible for at least a portion of the 360 circumference, but should not significantly restrict flow. Assemblies utilizing hoses made of harder durometer materials such as PVC and PTFE will likely not have a visible bulge. Also see Appendix G6. 3-A requires a slight bulge on at least one point around the 360 hose to hose barb junction point. For many crimp assemblies a bulge appears on one area of the hose first. It usually does not create a uniform bulge around the entire 360 circle. This is due to a few factors like the spiraling wire, thinner or thicker tube areas and varying OD s. Do not try to achieve a bulge around the entire 360 degree circle. This can lead to over crimping Sure Seal Crevice Free Hose Couplings have been designed, pressure tested and rated with finished couplings that meet the slight bulge requirement by 3-A. This overrides any specific crimp sleeve OD requirement. Creating the slight bulge achieves the two most important requirements for your assembly: 1) A Sanitary Crevice Free Junction Point 2) Strong Hose Barb Retention All approved Sure Seal Crevice Free Hose Coupling Distributors have received a 3-A Bulge Detection Toll with their start-up kit. Please use it to assist in meeting the sanitary slight bulge requirement. Page 1of 6
Bulge Detection Tool Included with your crimp guidelines is our 3-A Sanitary Hose Coupling Test Tool. It is perfectly designed to detect the first sign of the slight bulge that 3-A requires. Creating the slight bulge provides a sanitary and strong hose barb retention crimp. Also included with these guidelines is a cut-away sample of a 2 Crimp that has the slight bulge required by 3-A. It demonstrates how the tool easily detects the slight bulge required. Practice using the tool and aim for the same results with your crimps. Tool Usage The front end of the tool is shaped to match the angle of the circular tube. 1) Insert it into the tube and move it forward to the rubber and hose barb junction point 2) Feel for resistance moving forward as you push it. You will notice on the crimp sample that at some points you meet resistance moving forward. This tells you that the slight bulge has been created. If you can move your tool forward and pull it back where the tool grabs the back of the hose barb tells you there is no bulge in that area. Check the entire circle for the bulge. 3) During crimping the operator must stop before reaching a finished crimp. At this point the tool is used to check the interior junction point. From here forward the operator needs to do incremental crimping by engaging the close button one quick push at a time. Then check the interior with the 3-A Test Tool until the slight bulge is detected. Once you have your first sign of a bulge, the operator can use their best judgement to crimp a fraction or so more to slightly increase the bulge to insure a sealed 360 junction point. DO NOT try to create a bulge around the entire 360 circle. Some crimps may do so, but most do not. Trying to create a bulge around the entire tube will create a large bulge in one area and a smaller bulge in another. This could also lead to over crimping and Cold Flow as discussed below. 3-A only requires a slight bulge in one area. VERY IMPORTANT when using a Crimp Sleeve OD Formula Our Crimp Guidelines go beyond providing a Formula to crimp. We have seen multiple supposed sanitary crimps that do not meet 3-A Standards. Crimps that have not been crimped enough and many that have been crimped too much that end up with a large cold flow swollen blister (see below). Many of these are due to following a formula only without watching for and creating the slight bulge. Formulas alone cannot be relied on in meeting a Sanitary Crimp. This is because no two crimps are exactly alike. This is due to a few factors; 1) Location of the wire in the hose. 2) The inner tube is thinner or thicker in areas as it spirals around the tube. 3) Hose OD s can vary slightly Using the 3-A Tool and slight bulge procedure provides consistent matching sanitary crimps Page 2 of 6
Reduce or Eliminate Rubber Cold Flow Compressed rubber when deformed from its original shape always wants to move. This is one of the downsides of externally crimped hose couplings. See Photo: Cold Flow is the cause of the swollen rubber blister on this crimped hose coupling. This wipes out the meeting of 3-A sanitary requirements at the junction of the hose and hose barb Why Does It Happen? Not leaving room for the front of the hose to expand forward during crimping. If you push the hose all the way forward against the inside wall of the crimp sleeve it does not have room to expand forward. This causes the rubber to be pushed in the backward direction. Eventually it will move from under the sleeve to the end and create a much larger rubber bulge. The best solution to prevent this ALWAYS leave a ¼ to 5/16 space between the front of the hose and inside front wall of the crimp sleeve. All Sure Seal Hose Couplings (Clamp, Butt-Weld and Bevel with Nut) have the same Crimp Sleeve ID Length Inside Crimp Sleeve Hose Barb Length Inside Wall Crimp Sleeve Insertion Length Guide Measure the hose as required and place a mark. This is the mark you will push your crimp sleeve up to. It must always be at least ¼ back from the inner wall. Size Crimp Sleeve ID Measure hose ¼ Shorter 1.0 2-13/16 2-9/16 1.5 3-1/4 3.0 2.0 3-1/4 3.0 2.5 4-1/8 3-7/8 3.0 4-1/8 3-7/8 4.0 4-3/4 4-1-2 Page 3 of 6
Final Notes Sure Seal Crevice Free Hose Couplings are unique hose couplings. They allow easier insertion than most and we ve eliminated the handling and placement of crimp sleeves. They have been designed around meeting 3-A Guidelines for a crevice free interior junction point by creating the slight bulge requirement. 1) DO NOT OVER-CRIMP: Could lead to Cold Flow 2) DO NOT UNDER-CRIMP: Non-Sanitary Joint and less hose barb retention Use the 3-A Bulge Detection Tool. When reaching close to a finished assembly, the final OD is determined by reaching the point of creating the 3-A slight bulge requirement. 1) Once you reach a point of being close to a final crimp, conscientious fractional crimping is required to achieve the perfect sanitary crimp. 2) Insert the tool to see if resistance is met at any point of the inner junction point. Once a slight bulge is detected, use your best judgement to crimp a fraction more if needed. Create the slight bulge and you have a finished assembly that meets 3-A/USDA sanitary criteria and hose barb retention that will hold a minimum of 600 PSI Crimp Sleeve OD Formula We provide a formula that assists you in selecting a Crimp Die and one that provides an ordinary safe crimp, but not guaranteed to create the slight bulge. Consistency with a formula is impossible for a sanitary crimp. For an end user of a hose assembly who does not require a sanitary crimp the Crimp Sleeve OD Formula is the right tool. It is only a partial tool for meeting the requirements of a sanitary crimp The crimp Sleeve OD can be determined using the following formula Hose O.D. - Hose I.D. + Shank O.D. + (2 x Crimp Sleeve Wall Thickness) + [(-Hose Comp) x (Hose O.D. - Hose I. D.) / 100] Example: Crimp Diameter = 2.50-2.00 + 2.00 + (2 x.065) + [( -25) x (2.50-2.00) / 100] = 2.505 - + + (2 x ) + [ ( ) x ( - ) / 100] = Percentage of Compression: Recommended is usually between 20 to 25%. Generally the lesser percentage is for 250# thicker tube hose while the higher percentage is for the 150# harder hose. For creating a sanitary crimp you must stop short of the full percentage of crimping. Then allow final crimping as needed to create the bulge for a sanitary junction point. The table to the right provides you the Crimp Sleeve Wall Thickness for Sure Seal Crevice Free Couplings used for the crimp formula Sure Seal Size Sure Seal Hose Barb OD Sure Seal Crimp Sleeve Thickness 1 1.0.104 inch / 2.65mm 1.5 1.5.104 inch / 2.65mm 2 2.0.138 inch / 3.5mm 2.5 2.5.104 inch / 2.65mm 3 3.0.130 inch / 3.30mm 4 4.0.118 inch / 3.00mm Page 4 of 6
To the right is the Minimum and Maximum Hose ODs that Sure Seal couplings can be used safely with Important Note on Hose OD s: Max Hose OD. You can try the coupling on larger OD s. If they fit then you can proceed without issue Minimum Hose OD. Using coupling on smaller OD s could cause coupling collapse Crimp Procedure Hose ID Min Hose OD Max Hose OD 1 1.45 1.69 1.5 1.95 2.25 2 2.50 2.79 2.5 3.00 3.29 3 3.52 3.87 4 4.52 4.79 1) Cut the end of the hose perfectly straight This is very important to allow the hose to expand evenly forward to protect against cold flow. Also remove debris and rubber dust from the inside tube as this could affect hose barb retention. 2) Measure and mark your hose ¼ to 5/16 shorter than the inside length of your crimp sleeve (refer to chart) 3) Place your coupling onto the hose. Push the back end of the crimp sleeve to the mark placed on the hose. 4) Select the proper die size for the approximate final crimp OD required. Note: All Sure Seal Crevice Free Hose Couplings have a black indicator line to align your crimp die. Position your die right below the black line Page 5 of 6
5) With the hose and coupling positioned inside your crimp die, reduce the dies down so they gently squeeze the hose coupling right on the black line located on the hose coupling 6) Crimp the coupling to a point where you are close to a finished crimp, but short of creating the slight bulge THEN STOP Follow the next steps very closely Follow your 3-A Bulge Detection Tool usage guidelines. 7) Prepare to check your assembly for the slight bulge requirement using your 3-A Tool. Close the dies further by very small increments. Test for the slight bulge with each crimp die reduction. IMPORTANT At the first point of detection of the slight bulge continue crimping a fraction more at a time to insure a crevice free junction point. It is best to increase the bulge slightly to guarantee this. Most important thing is to not create a large bulge in one area and small bulge in another. Follow your standard procedures to pressure test final hose assemblies. RMA recommendations are 1.5 times hose rated pressure Key Industrial, 997 Enterprise Way, Napa, CA 94558 Phone: 800-852-5258 Fax: 707-252-9054 e-mail: sales@keyindustrial.com Page 6 of 6