Piping Technology & Products, Inc. recently custom designed and fabricated 63 variable spring assemblies used to support a boiler in a power plant. Three sets of custom springs were designed for this project. The first group measures 14 x 14 x 17 1/8 and can support 45,000 lbs. per inch. The next group can support up to 28,000 lbs. per inch and measures 16 x 16 x 17 11/16. The third group measures 15 x 15 x 17 9/16 and can support 38,000 lbs. per inch. The coils in the assembly are made from 2 15/16 diameter coil with 2 3/4 or 3 active coils.
The variable spring assemblies are carbon steel with an inorganic zinc primer finish. The spring coils are A4161-H material with a neoprene exterior coating. Each spring coil was tested to insure the wire diameter, coil height and spring rates met customer specifications.
Do you require custom variable spring assemblies like those described above? Get pricing today!
The disc-spring arrestors provide resistance by utilizing disc springs (sometimes referred to as Belleville® washers) stacked in a series within the assembly housing to produce a specific spring rate. By utilizing large (over 8 diameter) disc springs, very high spring rates may be obtained. The arrestors are capable of operating in both tension and compression.
The housing, end bracket, and extension pieces of the spring arrestor are made form A-36 carbon steel. The disc springs are made from ASTM A-1075 spring steel. One clamp (for design temp. of 688 degrees F.) was made from carbon steel and two clamps (for design temp. of 1054 degrees F.) were fabricated from A-387 GR.22 Chrome-Moly steel.
The diameter of each disc spring was 9 with a thickness of 1. The overall pin-to-pin dimension for the assemblies varied with a minimum of 35 and a maximum length of 57. The maximum length that can be accommodated is 120. The clamps were made for 18 and 30 diameter pipes.
The shock arrestor will see a maximum operating load of 43,000 lbs. The spring rate of each arrestor was designed at 40,000 lb./in. The spring arrestors are designed for a maximum displacement of 2. The arrestors were tested to verify spring rate and to confirm the operation of the pipe hanger assembly.
These supports are key components for the steam generators in a thermal power plant. The coils are coated with neoprene (black) to prevent corrosion while the steel plate and tie rods are painted white. Engineers of Piping Technology & Products, Inc. designed these units to support loads of 110,000 kips.