PT&P: On-Line Tour: Expansion Joints (1/2)

EXPANSION JOINTS (page 1 of 2)

OVERVIEW
Piping Technology & Products, Inc. offers a wide variety of expansion joint products and services. Whether you are replacing an existing joint or have just completed a new design, we can fabricate and test the unit to your specifications. When necessary, we will build prototypes and conduct tests to help evaluate units prior to installation.

Many expansion joints are custom-made for the particular application. The general categories we supply can be described by the materials used and the type of movement provided for.

ENGINEERING PROCESS
In order for PT&P to provide a quote, the customer must provide the following information: line size, operating and design pressure, operating and design temperature, design movements and type of end connections. Other information that is helpful but not necessary includes bellows material, flow media, overall lengths, required cycle life, required spring rates and the code used to base calculations on. (PT&P can provide ASME Code Stamp and U-2 Partial Data Reports.) Designers often request that the customer fill out the expansion joint data sheet (p. 28 of Expansion Joint Catalog) with as much information as possible.

Using the above information, the designer performs the Bellows Design Calculations to determine the appropriate/optimal bellows configuration. Inputs include bellows material, bellows internal and outside diameters, convolution height, pitch, number of convolutions, bellows thickness, number of plies, design pressure, design temperature, required cycle life, required movements and, if required, annealing, and root ring and collar information. Outputs include pressure thrust, actual cycle life based on concurrent movements, rated non-concurrent movements, actual and allowable stresses at critical locations of the bellows, spring rates, squirm pressure and test pressures.

Quality Control will need to know the tests to perform and the documentation they need to provide to the customer. This information can include dye penetrant testing, radiography, air or hydrotesting, magnetic particle examination, material certificates, U-2 partial Data Reports, U-Stamps and welding procedures.

In order for the shop to begin fabrication, they must have signed approval drawings which contain all the information necessary to build and QC the expansion joints. Often, the QC department must schedule meetings with the client's inspector and the ASME Code Inspector.

Continue PT&P On-Line Tour of Expansion Joints (Page 2 of 2)

From here, you can select another type of expansion joint you would like to see details on:

Metal Bellows: Metal bellows are the most common type of bellow. Follow this link to learn about how they're made.
Thick Wall: These may be cost-effective for large-diameter piping systems operating at low pressures, and have long lives which justify the initial investment. This portion shows some details of production.
Fabric: This type of expansion joint is often used in ducts which carry hot gases at low pressures. Come see some examples of manufacturing.
Slip Type: Some design details of this type of expansion joint include selection and packing of seals, and resistance to abrasive solids, or even "wipers" to prevent potential clogging of the space provided for slip movement. See how we make Slip-Type joints.
Rectangular: Rectangular expansion joints have a variety of uses in various industrial fields. See how PT&P can service the many needs our customers have on these applications.

Questions/Feedback

Related Links

Reference the on-line version of our Expansion Joint Catalog for more details.

Expansion Joints Submenu:
[ Metal Bellows | Thick Wall | Fabric | Slip Type | Rectangular ]

Piping Technology & Products, Inc.
Online Tour
P.O. Box 34506 / Houston, Texas 77234-4506 / U.S.A.
(713) 731-0030 / (713) 731-8640 (FAX)
www.pipingtech.com / info@pipingtech.com