made in the USA

Assembly Instructions

Figure 1
  1. Sealing Bulb
  2. Gasket Heel
  3. Stainless Steel Teeth
  4. Bell Ridge
  5. Retainer Seat
  6. Spigot/Plain End

1. Inspect and clean pipe and gasket. Ensure they are in good order, free from debris. Grind or file sharp edges that could damage the gasket when it is inserted. Carefully remove foreign matter such as tar or paint in the gasket groove.

In cold weather (40° F/4.4° C) it is more diffiult to clean surfaces but the removal of ice, dirt and debris is still required. Warming cold, stiff gaskets will ease assembly.

Figure 2

2. Insert the gasket. (Fig. 2) Loop the gasket and insert the rounded bulb-end first, placing the gasket heel in the retainer seat. Make sure not to install the gasket behind or underneath the retainer seat. Release the loop to allow the gasket to expand into the recess. Check with your fingers to be certain it is properly seated. Large gaskets may require multiple loops evenly spaced around the gasket.

Figure 3

3. Lubricate the spigot end and gasket. (Fig. 3) Apply a thin film of joint lubricant to the outside of the spigot end and to the surface of the gasket that will contact the spigot end. Do not lubricate the bell socket of the pipe or the surface of the gasket that contacts the bell socket.

Figure 4

4. Join the spigot end to the bell. (Fig. 4) Ensure the plain end of the pipe is beveled (See section on Field Cut Pipe) - square or sharp edges may damage or roll the gasket. Insert the spigot end into the bell and keep both sections of the pipe aligned without deflection. Insert pipe until the entire first assembly stripe has disappeared into the bell. After insertion to the first assembly stripe, the pipe can be deflected (See Table 2). Use a feeler gauge to ensure that the gasket has not been dislodged from proper placement during installation.

Figure 5

5. Reverse the assembly force. (Fig. 5) Apply a setting force in the opposite directon of assembly to engage teeth. Up to 0.25" of extension can be expected to set teeth. If the joint does not assemble properly, disassemble it and check for debris, proper positioning of the gasket, and adequate lubrication.

NOTE: The Gripper Gasket™ is not to be reused.

Figure 6

Use in casings: Pipelines restrained with Gripper Gaskets™ may be installed in straight casings by pulling, not pushing, the pipe through the casing. Assembly of the joints must be controlled, such as with come-a-longs or cable hoist, to prevent fully “homing” spigot to base of the socket to allow for joint deflection.

Field Cut Pipe

Figure 7

Bevel the edge of the field cut pipe ¼" at a 30° angle. Round the leading edge and remove sharp edges which could damage the gasket. When cut pipe with no assembly stripes is to be assembled, the spigot insertion depth should be marked on the spigot to ensure that the joint is fully assembled (See Table 2).

When deflection is required at the joint, the spigot should not be completely homed.

Pipe Diameters

Nominal Pipe Size
Pipe Diameter
Pipe Circumference
Minimum Maximum Minimum Maximum
3 3.92 4.00 12-5/16 12-9/16
4 4.74 4.86 14-7/8 15-9/32
6 6.84 6.96 21-15/32 21-7/8
8 8.99 9.11 28-1/4 28-5/8
10 11.04 11.16 34-11/16 35-1/16
12 13.14 13.26 41-9/32 41-21/32
14 15.22 15.35 47-13/16 48-7/32
16 17.32 17.45 54-13/32 54-13/16
18 19.42 19.55 61 61-13/32
20 21.52 21.65 67-19/32 68-1/32
24 25.72 25.85 80-25/32 81-7/32

Table 1. Suitable Pipe Diameters for Field Cuts and Restraint Joint Field Fabrication

Assembly Mark and Deflection

Pipe Size
Location Of Assembly Mark
Maximum Joint Deflection
Maximum Deflection Per Joint
18 ft. Laying Length 20 ft. Laying Length
3 2-5/8 19 21
4 2-3/4 19 21
6 2-15/16 19 21
8 3-1/4 19 21
10 3-5/16 19 21
12 3-5/16 19 21
14 4-9/16 15 16.5
16 4-9/16 15 16.5
18 4-9/16 15 16.5
20 5-1/16 2.5° 9.5 10.5
24 5-1/2 2.5° 9.5 10.5

Table 2. Assembly Mark and Deflection

Special Notes Regarding The Use Of Gripper Gaskets™

  1. Do not use Gripper Gaskets™ to provide electrical joint conductivity for thawing purposes. Such use may damage the gaskets.
  2. Use Gripper Gaskets™ only in push-on joints which have the trademark Tyton®, Trim Tyton® or Tyton Joint®. Use in other joints may result in joint separation.
  3. Gripper Gaskets™ should not be used in above ground installations.
  4. Do not use Gripper Gaskets™ with corroded pipe.
  5. Gripper Gasket LLC has not conducted tests with gray iron or plastic piping products and, therefore, cannot recommend or warrant the use of Gripper Gasket™ with gray iron (pipe, fittings or valves) or plastic (pipe or fittings).
  6. Always make sure the gasket is properly placed in the socket with the sealing bulb or thickest portion of the gasket being deepest in the socket.
  7. Use in casings: Pipelines restrained with Gripper Gaskets™ may be installed in straight casings by pulling, not pushing, the pipe through the casing. Assembly of the joints must be controlled, such as with come-a-longs or cable hoist, to prevent fully “homing” spigot to base of the socket to allow for joint deflection.
  8. Do not reuse Gripper Gaskets™.
  9. Do not use Gripper Gaskets™ with Tyton® Plugs since it is not possible to remove the plug after the joint is assembled.
  10. If the maximum joint deflection is necessary, do not push the pipe to the bottom of the socket.
  11. For cold weather assemblies, keep the temperature of the Gripper Gasket™ above 40°F.
  12. Approximately twice as much assembly force may be required to assemble a Gripper Gasket™ joint as is required for a conventional Tyton® Gasket push-on joint.
  13. The Gripper Gasket™ should not be used on pipe and fittings which have thick coatings or tape wrap on the outer diameter of the pipe. In general, if the peen pattern is not visible on the pipe surface, the asphalt coating may be too thick for proper penetration of the teeth of the Gripper Gasket™. The thick coating should be removed from the end of the pipe or fitting before assembly. The coating must be no more than 2 mils thick for asphalt coating and 6 mils nominal thickness for 2 part epoxy coating on the plain end of the pipe.
  14. Concrete Thrust blocking or other means of thrust restraint is not required to be used with Gripper Gaskets™ when Gripper Gaskets™ are used in a designed thrust restraint system. The Thrust Restraint Design for Ductile-Iron Pipe published by the Ductile-Iron Pipe Research Associatin (DIPRA) is one method used to calculate the required length of restraint at a change in direction. This program is available online at
    Pressure Rating: The working pressure rating of the Gripper Gasket™ Restrained Joint System does not exceed that of the working pressure rating of the pipe in which it is installed.
  15. If Gripper Gaskets™ are used in vertical installations, provisions must be made to keep the joint extended and not allow the teeth to become disengaged from the pipe. Failure to keep vertical joints extended can result in joint separation.
  16. For cut pipe, select pipe with diameters or circumferences at the cut location which conform to Table 1 above.
  17. For cut pipe, ensure that a tapered bevel similar to the one furnished with the pipe is ground onto the end of the pipe.
  18. Measure the socket depth and make a mark on the pipe spigot that distance from the end of the pipe. This mark will indicate when the joint is fully “home”.
  19. Keep the joint in straight alignment during assembly, especially when handling fittings. Do not fully “home” the joint if maximum joint deflection is required. Set the joint deflection after the assembly is made.
  20. Check for correct positioning of the Gripper Gasket™ by inserting a feeler gauge in the space between the bell and the pipe OD in several locations around the socket to assure that the gasket is in proper position in the socket.
Correct and Wrong

Tyton® and Field Lok® are registered trademarks and properties of United States Pipe and Foundry Company, LLC. Gripper Gasket, LLC is not affiliated in any way with United States Pipe and Foundry Company, LLC.