11 02/18 Thrust blocks must be designed for maximum anticipated operating or test pressure. If it is anticipated that pressures higher than normal operating pressures will be used at some later date, thrust blocks to accommodate such pressures should be installed initially. Size and type of thrust blocks depend on pressure, pipe size, and the type of soil. This information shall be supplied by the Design Engineer. Where a thrust block serves more than one line, the block must be designed to resist the sum of the thrusts of all the lines involved. Thrust blocks shall be installed using a concrete having a compressive strength of not less than 3,000 psi minimum ultimate 28 days compressive strength, air entrained, with water reducing admixture. Where the soil bearing value is less than 1,000 pounds per square foot, Thermal Pipe Systems, Inc. will make the necessary calculations and recommendations as to how the fitting should be thrusted. Where special thrust provisions are needed, Thermal Pipe Systems, Inc. will recommend the necessary design. The table below gives the thrust load at any fitting. Thrust blocks should be poured on and against undisturbed soil or soil tamped to 95% proctor density. SUPER TEMP-TITE FITTINGS Thrust at fittings (for concrete thrust blocks) in lbs. at 100 psi* pressure: Size (in.) Tee 90 Elbow 45 Elbow Reducer** 3 985 1,395 755 4 1,620 2,295 1,245 4x3 680 6 3,500 4,950 2,680 6x4 2,060 8 5,930 8,375 4,540 8x6 2,700 10 9,076 12,833 6,963 10x8 3,680 12 12,765 18,000 9,700 12x10 4,360 *For pressure other than 100 psi increase loads proportionately (example: for 150 psi multiply by 1.5; for 200 psi multiply by 2.0: etc.) **This is for the size difference indicated (ex. 4x3 = 680 lbs) NOTE: Dead End and Anchor loads are equal to TEE shown above.