11 02/18 THRUST BLOCKS: Thrust blocks must be installed wherever the pipeline changes direction or size as at tees, elbows and reducers or at any point that develops thrust such as at a valve or similar equipment. The above situations may occur either where the fittings etc., are directly buried in the soil, or are in a manhole. 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 of the lines involved. Thrust blocks should be poured on and against undisturbed soil or soil tamped to 95% proctor density. Thrust blocks shall be installed using a concrete having a compressive strength of not less than 3000 psi minimum ultimate 28 days compressive strength, air entrained, with water reducing admixture. Where the soil bearing value is less than 1000 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. COPPER CORE FITTINGS: The table below gives the thrust load at any fitting in lbs. at 100 psi* pressure. Size (in.) 90º Elbow 45º Elbow Tee 1 115 60 80 1 1/4 175 95 125 1 1/2 250 135 175 2 425 230 300 2 1/2 675 370 480 3 960 525 680 4 1695 925 1200 6 3998 2165 2828 *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.) NOTE: Dead End and Anchor loads are equal to tee shown above.