Support spacing

Support spacing must be much closer than for carbon steel. As temperature increases, the allowable stress for many plastic pipes decreases very rapidly, and heat from sunhght or adjacent hot uninsulated equipment nas a marked effec t. Successful economical underground use of plastic pipe does not necessarily indicate similar economies outdoors aboveground. 

Mechanical vibration of pipe is handled in the same manner as for reciprocating pumps (Volume 1, Chapter 12). Normally, if the pipe support spacing is kept short, the pipe is securely tied down, the support spans are not unifoiTn in length, and fluid pulsations have been adequately dampened, mechanical pipe vibrations will not be a problem. It is good practice to ensure that the natural frequency of all pipe spans is higher than the calculated pulsation frequency. The pulsation frequency is given by ... 

Pipe support spacing affecting local bending... 

S.S. (2002) Technology roadmap for dual-mode scramjet propulsion to support space-access vision vehicle development, Paper No. AIAA-2002-5137, 11th AIAA/AAtAF Inter. Space Planes... 

If the proposal needs an institutional match, a meeting with the department chair, dean and perhaps the provost should be set up before submitting the proposal. The researcher will need to clarify precisely what is expected from the grant agency for this match, whether it be tuition assistance, administrative support, space and/or reduced teaching load. Even if the RFP does not specify an institutional match, it can be helpful to obtain some matching funds or equipment. 

Equation 9.1 assumes equal support spacings in both directions. 

Pipe support configurations are an important facet of design. A small increase in diameter greatly increases the flexural rigidity of a pipe span, which is proportional to d, and therefore increases the permissible support spacing (the load of the fluid content increases only as d. Support considerations are rather different in the case of plastic pipes, which often need full-length support in the smaller sizes to avoid excessive deflection and bending stresses. 

Support personnel located on the tower began rescue efforts. There were three hatches for the command module, making quick access difficult. One was to jettison after launch. Hames filled the command module. A rupture occurred in the module and flames, gases and smoke flowed into the support space, called the White Room. Thick smoke in the White Room hampered attempts to open the hatches. 

An alternative numerical method for resolving complicated signals is to analyze the frequency spectrum of the curves. The so-called Fourier transform analysis (FT analysis) approximates the sum of sine and cosine functions for empirically generated signals. First, 2 m points of supports, spaced equidistantly, are chosen (Fig. 2-2). We recommend choosing a multiple of four for 2 m and using the values 12, 24, 36, 72,. .. 

There are many successful applications of this type, but nevertheless to move from these to a complete space frame would still be a big conceptual leap. The perceived wisdom at the present time is that any car body made up of individual panels must be based on a supporting space frame, and that the frame structure should be made of steel, or conceivably aluminium. Space frames in aluminium have in fact been used to support plastics panels in several concept cars, from the BL ECV-3 of the early 1980s to GE Plastics Ethos II of 1993. 

However, the spacing of the pipe supports must also be such that the deflection between supports does not exceed i in. This requires an analysis of the creep that may be expected with any proposed pipe-support spacing specification. The elastic deflection of the midpoint of continuous pipe between supports is calculated as... 

TABLE 5.56 Typical Recommended Maximum Support Spacing, in Feet, for Thermoplastic Pipe for Continuous Spans and for Uninsulated Lines Conveying Fluids of Specific Gravity up to 1.35... 

Mikulecky P (2009) Remarks on Ubiquitous Intelligent Supportive Spaces, 15th American Conference on Applied Mathematics/Intemational Conference on Corrrputadonal and Itrformadon Science, Univ Houston, Houston, TX, pp. 523-528, ISBN 978-960-474-071-0... 

Plastic pipe systems should be isolated from sources of vibration such as pumps and motors. Vibrations can negatively influence the integrity of the piping system, particularly at joints. Support spacing for several types of plastic pipe are found in Figures 4.8,4.9, and 4.10. Spacing is dependent upon the temperature of the fluid being carried by the pipe. 

Nominal Pipe Size, inch Maximum Support Spacing, ft at60°F Maximum Support Spacing, ft atSO -F Maximum Support Spacing, ft at I00°F Maximum Support Spacing, ft at 120°F Maximum Support Spacing, ft at I40°F ... 

FIGURE 4.8 Support spacing for schedule 40 PVC pipe. Maximum support spacing in feet at various temperatures. 

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