Design pipe joint

A passive design must include all hardware elements of the system. Little is gained if containment is lost when pipes, joints, or instruments fail due to overpressure. 

In addition, they are usually constructed without isolation valves on the fuel supply lines. As a result the final connection in the pipework cannot be leak-tested. In practice, it is tested as far as possible at the manufacturer s works but often not leak-tested on-site. Reference 32 reviews the fuel leaks that have occurred, including a major explosion at a CCGT plant in England in 1996 due to the explosion of a leak of naphtha from a pipe joint. One man was seriously injured, and a 600-m chamber was lifted off its foundations. The reference also reviews the precautions that should be taken. They include. selecting a site where noise reduction is not required or can be achieved w ithout enclosure. If enclosure is essential, then a high ventilation rate is needed it is often designed to keep the turbine cool and is far too low to disperse gas leaks. Care must be taken to avoid stagnant pockets. 

Prior to initial operation, each piping installation, including components and workmanship, shall be examined in accordance with the applicable requirements of Part GR and the specific requirements of Part IP or PL, and to any greater extent specified by the engineering design. Weld joints not included in the extent of examinations required by Part IP or PL or by the engineering design are acceptable if they pass VT and the leak test required by para. GR-4.10. 

If anchorage is not provided at the bend (see para. PL-2.8.2), pipe joints that are close to the points of thrust origin shall be designed to sustain the longitudinal pullout force. If such provision is not made in the manufacture of the joints, bracing or strapping that absorbs the pressure thrust shall be provided. 

ISO 1872-1 1993 Plastics - Polyethylene (PE) moulding and extrusion materials - Part 1 Designation system and basis for specifications ISO 1872-2 1997 Plastics - Polyethylene (PE) moulding and extrusion materials - Part 2 Preparation of test specimens and determination of properties ISO 1969 2004 Fibre ropes - Polyethylene - 3- and 4-strand ropes ISO 3458 1976 Assembled joints between fittings and polyethylene (PE) pressure pipes -Test of leakproofness under internal pressure ISO 3459 1976 Polyethylene (PE) pressure pipes - Joints assembled with mechanical fittings - Internal under-pressure test method and requirement ISO 3501 1976 Assembled joints between fittings and polyethylene (PE) pressure pipes -Test of resistance to pull out... 

Piping design, materials, joint fabrication, examination, and inspection shall be in accordance with ANSI/ASME B31.3. 

One of the most applied high-pressure standards for the piping components is based on the so--called IG-Standard, which was established by an association of the German Chemical Industry beginning with 1930. Similar developments took place in the US and elsewhere. The pipes applied are of seamless design. The joints and seals which have been approved for high-pressure are shown in Fig. 4.2-1. 

The VOC emissions occur from leaks around from valve stems, pump shafts, worn packings, and pipe joints. Fugitive VOC emissions can be minimized with proper design and specifying seal-less pumps and valves, and with good preventive maintenance. 

The preferred design of joints in piping system to avoid crevices is depicted in Figure 1.53. 

Some chloroacnegens, such as 3.4, are so potent that drug companies hesitate to work with them.46 The widespread use of triclosan (3.5) as a bactericide in personal care products needs to be reduced now that several strains of bacteria resistant to it have been isolated.47 Soap and water alone will suffice in many of these applications. The use of dichlobenil (3.6) to kill roots penetrating underground pipes might be eliminated by designing tighter pipe joints.48... 

Piping tierods are used to restrain the anchor force produced by the particular group of pipe-joints which tend to pull apart when subjected to internal pressure. Figure 1-135 shows a typical tierod design. 

Stress relaxation is an important design consideration for sealing applications from O-rings to pipe joints for water, gas, and petroleum pipelines. However, like creep, it has been a relative latecomer in material and product specifications, again largely because of a previous reliance on suitably resistant rubber types. The development of performance-... 

Field Hydrostatic Testing. Field hydrostatic testing is not an ASME Code requirement. Field testing is optional to test the tightness of piping joints attached to the vessel after installation. Often it is a contractor s policy to design vessels and vessel foundations, with rare exceptions, for a future field hydrotest in the corroded condition. This gives clients the option to test the vessel on its foundation in the future should alterations or repairs warrant such a test. 

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