Stress allowable working

Find the maximum allowable working stress if this is to equal... 

Maximum Allowable Working Pressure -As defined in the construction codes for pressure vessels, the maximum allowable working pressure depends on the type of material, its thickness, and the service conditions set as the basis for design. The vessel or equipment may not be operated above this pressure, or its equivalent stress at any other metal, temperature. However, ANSI B31.3, Petroleum Refinery Piping Code, permits variations above the maximum allowable working pressure, as follows ... 

The allowable working stress, based on successful performance at conditions of product usage. 

An important subject to introduce concerns the allowable working stress for a spe-... 

The viscoelastic nature of the material requires not merely the use of data sheet information for calculation purposes, but also the actual long-term performance experience gained that can be used as a guide. The allowable working stress is important for determining dimensions of the stressed area and... 

The next step is to determine an allowable working stress. This is done by using a safety factor usually of IV2 to 2V2 on the yield strength or tensile strength. If the type of stress is clearly defined, the IV2 factor is adequate otherwise, it should be higher (Chapter 2, Safety Factor). 

The final step is to calculate the elongation that the product would experience under the selected allowable working stress to see if such an elongation would permit the proper functioning of the product. The elongation could conceivably become the limiting component, and the working stress can be calculated from ... 

When materials are evaluated against each other, the flexural data of those that break in the test cannot be compared unless the conditions of the test and the specimen dimensions are identical. For those materials (most TPs) whose flexural properties are calculated at 5% strain, the test conditions and the specimen are standardized, and the data can be analyzed for relative preference. For design purposes, the flexural properties are used in the same way as the tensile properties. Thus, the allowable working stress, limits of elongation, etc. are treated in the same manner as are the tensile properties. 

The stress levels and the temperature of the test for a material is determined by the manufacturer. The guiding determinants are the continuous allowable working stress at room temperature and the continuous allowable working stress at temperatures of potential applications. 

Pipe schedule number = 1000P/S, approximately, where P is the internal pressure psig and S is the allowable working stress (about 10,000 psi for A120 carbon steel at 500°F). Schedule 40 is most common. 

Allowable working stresses are one-fourth of the uitimate strength of the materiai. 

In designing a spring, the maximum stress must not exceed the allowable stress or working stress of the material (Roark and Young, 1975). These formulas are useful in the design of vibration isolation systems. 

S = maximum allowable working stress, lbf/in.2 5, = cross-sectional flow area in upstream section of duct before constriction, ft2... 

It has been emphasized already that you should be familiar with the regulations and codes of practice pertaining in your laboratory. We will not discuss safety legislation here but some fundamental rules should be stressed. Never work alone in a laboratory. Always wear suitable safety spectacles and a cotton lab coat, and use other protection such as gloves, face masks, or safety shields if there is a particular hazard. Never eat, drink or smoke in a laboratory. Work at a safe, steady pace, and keep your bench and your lab clean and tidy. Familiarity breeds contempt do not allow yourself to get careless with everyday dangers such as solvent flammability. Familiarize yourself with the location and operation of the safety equipment in your laboratory. 

Table I gives the maximum allowable working pressure, in psig, ba.sed on an allowable stress ol 15,000 psi. fo correct for the specific material and temperature,...

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