How To Select and Order

The first step in selecting the proper expansion joint assembly is to collect and organize as much information regarding the design and operating parameters of the system as possible. As a minimum the following information should be provided:

• Size of the line.

• Design pressure.

• Design temperature.

• Design movements and required cycle life.

• Overall length requirement, if any.

• Type of end connections.

• Bellows material.

• Pipe material.

• Flange specification and material.

• Type of expansion joint.

• Accessories.

EXAMPLE

1. Assume the following expansion joint design criteria:

a) Line size: 18-inch nominal diameter.

b) Design/operating pressure: 300 psig.

c) Design/operating temperature: 550°F.

d) Movements/cycle life

Installation: 0.25-inch lateral; 0°angulation, 0-inch axial. Start-up/shut down: 1.13-inch lateral; 0°angulation, 0-inch axial, 1,000 cycles. Excursion: 2.05-inches lateral, 0°angulation; 0-inch axial, 200 cycles.

The thermal growth of the pipe between the tie rods must be considered when designing the bellows of an expansion joint with 60-inches O.A.L. The thermal expansion of carbon steel pipe at 550°F is 0.21-inch. The corresponding expansion for the excursion conditions is 0.38-inch.

e) End connections: Weld ends (standard bevel); 18-inches standard weight pipe (0.375-inch wall).

f) Bellows material: A-240-T321.

g) Type: Tied.

h) Accessories: Liner.

2. Turn to the Conversion Factor Graph and calculate equivalent catalog movements.

Total = 0.38 2.15 0

3. Refer to page 82, 18-inch nominal diameter universal U-Flex expansion joints, and go to the lowest pressure rating that is equal to or greater than specified design pressure (300 psig). Compare the total equivalent catalog movements to those shown in the catalog, keeping in mind that the tabulated movements in the catalog are for 3000 cycles for one movement only.

4. Select the shortest overall length that by inspection would appear to meet the movement criteria. Use the following formula to determine if the selected overall length is acceptable.

EQUIV. AXIAL EQUIV. LATERAL EQUIV. ANGULAR

RATED AXIAL RATED LATERAL RATED ANGULAR

400 psig rating/60-inch O.A.L.

0.38 2.15 0.00

1.98 3.16 0.00

5. Since 0.87 is less than 1.0, the 400 psig/60-inch O.A.L. will meet the criteria for all the movement conditions specified in Step 1.

6. Include the designations for the type (TU for tied universal), and liner (L), in the part number. All of the actual movements must be specified when combination ends are specified.

7. On combination end units, the direction of flow must be specified.

8. The resulting PT&P part number would then be as follows: