You have questions about Expansion Joints and Piping Accessories? Bob has answers. Just send him an e-mail, and he will post your question and his answer.

Q. What information is needed to design an Expansion Joint?
(1) Size of the existing piping/ducting and mating fittings.
(2) Maximum service temperature.
(3) Material of the flexible element and end connections.
(4) Motion requirements (axial, lateral, angular) or other special conditions.
(5) Design Pressure.
(6) The overall length of the completed assembly.

Q. Can Expansion Joints be designed without all of the above information?
Probably. Most Expansion Joints applications are for replacement of existing units. Many of these units have original equipment part numbers stamped on them that can be used to determine the design requirements. If you can not find markings don't give up, call us and we will find a solution to your problem.

Q. Why do bad things happen to good Expansion Joints?
Most of the time, it’s because all of the system information was not provided at the design stage. Bad things can also happen as a result of improper guiding of the piping around the Expansion Joint. The introduction of an Expansion Joint into an improperly guided piping system will cause the Expansion Joint to fail prematurely. If you are replacing an existing Expansion Joint, you probably do not have to worry about the guiding. If you are introducing an Expansion Joint into an old system for the first time or designing a new system you should consult the Expansion Joint Manufacturer for proper guiding requirements.

Q. What are some other reasons for premature Expansion Joint failure?
The number one cause of Expansion Joint failure is from corrosion. The material selection of the bellows is very important since the thickness of the Bellows in relationship to the surrounding piping is quite thin. Bellows material is ideally provided by the End User because of the many variables in the selection process including concentrations, and possible combinations of different media. Bellows material is determined by a Metallurgist based on a number of things not normally available to the Expansion Joint Manufacturer. When replacing an existing Expansion Joint that has had a satisfactory life it recommended that you use the same bellows material that has been in service.