Piping system installation

Pipe systems installed in a water environment require design consideration for external hydraulic pressure, submergence weighting, and floatation. Any river, lake or stream crossing is considered a water environment. Wetlands and marshes are also considered water environments. 

Similarity shall be assumed for two systems if the difference in dimensions is within the acceptable tolerance limits set forth in PVRC WRC Bulletin 316, Technical Position on Piping System Installation Tolerances, (July 1986).,... 

Enough space must be available to properly service the flow meter and to install any straight lengths of upstream and downstream pipe recommended by the manufacturer for use with the meter. Close-coupled fittings such as elbows or reducers tend to distort the velocity profile and can cause errors in a manner similar to those introduced by laminar flow. The amount of straight pipe required depends on the flow meter type. For the typical case of an orifice plate, piping requirements are normally Hsted in terms of the P or orifice/pipe bore ratio as shown in Table 1 (1) (see Piping systems). 

The selection and appHcation of an expansion joint is not as simple as selecting a pipe fitting or a valve and requires a sound understanding of the joint s capabihties and limitations. Improper appHcation of any type of joint can result in serious or damaging effects. However, when properly selected and integrated into the piping system, satisfactory service and safe operation can be expected. Selection and appHcation of beUows expansion joints require special attention to design and installation. 

Another way to study corrosion in pipe lines is to install in the line short sections of pipe of the materials to be tested. These test sections should be insulated from each other and from the rest of the piping system by means of nonmetalhc couphngs. It is also good prac-tice to provide insulating gaskets between the ends of the pipe specimens where they meet inside the couplings. Such joints may be sealed with various types of dope or cement. It is desirable in such cases to paint the outside of the specimens so as to confine corrosion to the inner surface. 

At the Lipari Landfill site in New Jersey, the gas venting system installed in 1983 consisted of two underground 4-inch (10-cm) perforated PVC pipes and five vent risers. Two parallel PVC pipes were installed 200 feet apart prior to cap emplacement during the period of wall construction and were placed about 3 feet beneath the finished grade. The vent risers were connected to the buried manifold pipes and consisted of open pipe installed perpendicular to the underground pipes and the ground surface. Filters were not attached to the riser exit points (U.S. EPA, 1987). 

Piping systems should be designed to minimize the use of components that are likely to leak or fail. Sight glasses and flexible connectors such as hoses and bellows should be eliminated wherever possible. Where these devices must be used, they must be specified in detail so they are structurally robust, compatible with process fluids, and installed to minimize the risk of external damage or impact. 

Snppressant harrier systems have the same shortcomings as cited in Section 3.6. In addition, the location of the sensor is critical to the snccessfnl isolation of a deflagration flame in a piping system. Bartknecht (1981) states that the flame sensor is installed at a distance of 1 meter from the ignition sonrce, and the extingnisher nozzles at a distance of 10 meters from the ignition sonrce. 

Broschka et al. (1983) report results of experimental tests on parallel plate flame arresters in piping systems. Tests were conducted on 3-inch and 6-inch diameter parallel plate flame arresters installed in 3-inch and 6-inch diameter piping sections using butane-air mixtures to generate a flame. The ignition source was varied from 3 to 43 feet from the flame arrester. The flame speed varied between 0 to 20 ft/s, and when the flame speed was 20 ft/s, the flame passed through the arrester (flame arrester failure). 

The total piping system pressure drop for a particular pipe installation is the sum of the friction drop in pipe valves and fittings, plus other pressure losses (drops) through control valves, plus drop through equipment in the system, plus static drop due to elevation or pressure level. For example, see Figure 2-2. 

Consider any risers that may be installed in the piping system. In considering risers, use resonant calculations for a closed tube (C/L) and investigate the open-end tube (C/2L). 

API Recommended Practice 14E, Fifth Edition Recommended Practice for Design and Installation of Offshore Production Platform Piping Systems, October 1991. 

Figure 6.12 Multiple piping system anchor of guide installation (courtesy of Industrial Hangers Ltd)...

Code of Practice No. 22, LPG piping system design and installation... 

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