EJMA Standards: The Authority on Expansion Joints The EJMA Standards Receive a Free Copy of A Practical Guide To Expansion Joints With each printed . Good Morning friends, I was looking for EJMA 9th Edition Standard. Can someone please provide me this Standard (9th or 8th edition as well)? Petroleum Community Forum -Free Discussion and Education Community. I need EJMA Standard 10th Edition? Can anyone share? Petroleum Community Forum -Free Discussion and Education Community. Help.
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Definitions in the Nomenclature section 1.
Bellows meridional bending stress due to pressure. Fre is the displacement of the longitudinal axis of the Expansion Joint from its initial straight line position into a circular arc.
Zero length is shown for single bellows. EJMA was founded in to establish and maintain quality design and manufacturing standards. Bellows circumferential membrane stress due to pressure. The Authority on Expansion Joints The EJMA Standards are recognized throughout the world as the authority on the proper selection and application of metallic bellows type expansion joints for stxndards and reliable piping and vessel installation.
EJMA 10th Edition
Bellows E at Temperature: In-plane squirm is defined as a shift or rotation of the plane of one or more convolutions such that the plane of these convolutions is no longer perpendicular to the axis of the jema. Excessive internal pressure may cause a bellows to become unstable and squirm. Total length of the expansion joint including the possible pipe ends.
The bellows resistance factor or working spring rate is shown in dree per inch of lateral offset.
The calculation of universal type Expansion Joints has been simplified by a modified equation for the axial movement per convolution. Bellows material thickness for one ply, corrected for thinning during the forming of the bellows convolutions. Calculated maximum pressure in PSIG before wtandards joint may squirm because of column instability.
Cycle Life is theoretical and is dependent upon the maximum stress range to which standzrds bellows is subjected. In order to evaluate the fere upon piping, supports, or equipment, it is necessary to determine the axial forces and moments required to move an Expansion Joint.
Axial Working Spring Rate: The Guide is intended to provide users with a basic understanding of expansion joints. The number of fatigue cycles can now be calculated from the same set of fatigue curves which are relevant for the unreinforced bellows and for the toroidal bellows.
Total Equivalent Max Axial: Bellows pitch and height tolerances were redefined relative to diameter. Squirm is detrimental to bellows performance in that it can greatly reduce both fatigue life and pressure capacity. Allowable material stress at design temperature, unless otherwise specified, from the applicable code. Joints Externally Pressurized Exp.
Single Bellows Axial Vibration Constants were revised. Factor establishing relationship between the equivalent axial displacement per convolution due to lateral deflection. Collar circumferential membrane stress due to internal pressure.
EJMA 10th Edition
The fatigue life expectancy can be defined as the total number of complete cycles which can be expected from the expansion joint. Yield strength at design temperature, unless otherwise determined, of bellows material after completion of bellows forming and any applicable heat treatment. Bellows are rated by the manufacturer in terms of maximum allowable axial displacement per convolution, ec and ee.
Fatigue life calculations were greatly enhanced and simplified. Bellows Yield at Temp: Tightness of bellows, bands, and rings due to dissimilar material growth rates is considered. This condition is most associated with bellows which have a relatively large length-to-diameter ration and is similar to the buckling of a column under compressive load.
In order to evaluate the loads upon piping, supports, or equipment, it is necessary to determine the lateral forces and moments required to move an Expansion Joint. This condition is predominantly associated with high meridional bending stress at the root and crest of the convolutions.
Distance between outermost ends of the convolutions in a universal expansion joint. Bellows meridional membrane stress due to deflection. To order click here.
It is calculated as either Lb or Lu plus length of pipe ends. EJMA 10th Edition is the most current edition and supersedes all previous publications. A cycle is defined as one complete movement from the initial position in the piping system to the operating position and back to the initial position. Bellows meridional bending stress due to deflection. The Tenth Edition standards combine the knowledge and experience of the leading manufacturers of expansion joints into an invaluable reference document.
Expansion Joints Exhaust Flanges. The fatigue life expectancy of an expansion joint is affected by various factors such as: Modulus of Elasticity at design temperature, unless otherwise specified, for material. It will also assist the user in communicating design requirements to the manufacturers and to properly install and maintain the expansion joint in service.
Benchmark table inputs and outputs have been revised, with material class and correction factor.
ejms Any change in these factors will result in a change in the life of the Expansion Joint. Bellows tangent circumferential membrane stress due to internal pressure.