Pipe supports design

Pipe support design should be given special attention. It may be desirable to increase pipe diameter to provide more pipe strength and rigidity and make it possible to have greater... 

FIG. 10-174 Typical pipe supports and attachments. (From Kellogg, Design of Piping Systems, Wiley, New York, 1965.)... 

Proceed with design of pipe supports and stress analysis, if required. 

Compressible fluid flow occurs between the two extremes of isothermal and adiabatic conditions. For adiabatic flow the temperature decreases (normally) for decreases in pressure, and the condition is represented by p V (k) = constant. Adiabatic flow is often assumed in short and well-insulated pipe, supporting the assumption that no heat is transferred to or from the pipe contents, except for the small heat generated by fricdon during flow. Isothermal pVa = constant temperature, and is the mechanism usually (not always) assumed for most process piping design. This is in reality close to actual conditions for many process and utility service applications. 

Design of vessel and vent line pipe supports is very important because very large forces can be encountered as soon as venting begins. Figure 4 shows the equations and nomenclature to calculate forces on pipe bends. The authors have heard of situations where vent line bends have been straightened, lines broken off, or vent catch tanks knocked off their foundations by excessive forces. For bends, the transient effects of the initial shock wave, the transition from vapor flow to two-phase flow, and steady state conditions should be considered. Transient conditions, however, are likely to be so rapid as to not have enough dura-... 

Various designs of pipe hangers and supports are used to support individual pipes. Details of typical supports can be found in the books by Perry et al. (1997) and Holmes (1973). Pipe supports frequently incorporate provision for thermal expansion. 

The design of support structures (not covered by this Code) and of supporting elements (see definitions of piping and pipe-supporting elements in para. GR-1.5) shall be based on all concurrently acting loads transmitted into such supports. These loads, defined in para. IP-2.1, include weight effects, loads introduced by service pressures and temperatures, vibration, wind, earthquake, shock, and displacement strain [see para. IP-6.1.3(a)]. 

For example, if LPG vessels are considered to be within a fire-scenario envelope, they require fireproofing unless protected by a fixed water spray system. API Standard 2510, Design and Construction of Liquefied Petroleum Gas Installations (API, 2001) recommends fireproofing pipe supports within 50 ft (15 m) of the LPG vessel, or within the spill containment area. 

Effects of Support, Anchor, and Terminal Movements The effects of movements of piping supports, anchors, and connected equipment shall be taken into account in the design of piping. These movements may result from the flexibility and/or thermal expansion of equipment, supports, or anchors and from settlement, tidal movements, or wind sway. 

Pipe Supports Loads transmitted by piping to attached equipment and supporting elements include weight, temperature- and pressure-induced effects, vibration, wind, earthquake, shock, and thermal expansion and contraction. The design of supports and restraints is based on concurrently acting loads (if it is assumed that wind and earthquake do not act simultaneously). 

Pipe supports should provide appropriate slopes for drainage and should be designed to support the piping adequately under worst-case thermal conditions. 

Limiting noise levels is not restricted to the SRV alone (Figure 8.5). Design of piping and, in particular, the isolation downstream and pipe supports are generally greater contributors to noise than the SRV itself. 

Stationary percolation is conducted in a tank or a series of countercurrent-flow tanks with perforated bottoms to support the solid particles and permit drainage of the solution. To allow filling and discharge of one tank at a time without disturbing the continuous operation of other tanks, the piping is designed so that the solvent can be introduced to any tank and the solution can be withdrawn from any other tank simultaneously. 

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