Pipes suppliers

Pipe roughness, or friction factor /, can be obtained with the pipe supplier or in piping books. As a reference, commercial steel piping roughness is assumed 0.00015 ft for schedule 40- and 80-type pipes. The following table provides some guidance but is not to be used as reference. 

Table 4.1 Major Pipe Suppliers in the European K flarket ...

There have been two different but equally successful precedents for implementing quality assurance in Europe. In the UK and France, large gas and water utilities were able to create corporate standards to apply through purchase and supply contracts within a customer/contractor relationship with pipe suppliers. In Germany, the proliferation of local authority owned gas and water utilities meant they were too small to impose corporate standards. Instead, the contractual relationship with the larger pipe supply companies was maintained by standards set by third parties such as the German DVGW, supported by independent test houses. 

There is a method the engineer can use for this analysis, but it is extremely complex and can be most conveniently checked by the pipe supplier, using a computer. In general, equations are generated to determine the moment and thrust created in the invert area of the deflected pipe, where a pressure term is superimposed. This analysis must examine the strains in the outer- and innermost fibers of the pipe to verify that its wall structure is adequate and not overstrained (see Fig. 5-24). During this analysis the pipe must be examined under conditions of no pressure, minimum pressure, and maximum pressure. 

Equipment test pressures are often specified in the design documentation. Piping test pressures can be set by discussion with the plant designer or piping supplier. At least two independent pressure gauges of known acciuacy should be used. Before beginning the pressure test for equipment integrity, it may be useful to apply a low pressure test with compressed air to check for faulty coimections. 

The basic principle of the installation of buried plastic piping is to embed it in a soil of such quality that the resultant ultimate pipe deflection is controlled to an acceptable value that is limited by either the pipe performance requirements or the pipe material capabilities. The former generally permits deflection up to about 10 percent (some engineers may set conservatively lower values) while the latter is determined by the maxunum allowable stress, or strain, in the pipe wall for the given pipe material and construction.The pipe supplier can provide the limiting deflection values for a given pipe material and construction. These values may depend on the fluids being handled. With thermoplastic pipe of solid wall construction deflection will seldom be limited by material performance constraints. 

Hazen-Williams formula from small to large pipes. Despite the fact that commercial publications from pipe suppliers sometimes use ... 

The manufacturing and assembly of the pipes may be assigned to several subcontractors. This depends decisively on the number and kind of piping classes used. Thus a separation into metal pipes and plastic pipes is thinkable. If several pipe suppliers are commissioned, the clarification of the numerous interfaces and the avoidance of mutual hindrances at the buildtng site may turn out to be difficult. 

Two suppliers to the U.S. market are Bayer and Nippon Zeon. The estimated volume used in the United States is 500 700 t/yr. Hydrogenated nitrile mbber (HSN or HNBR) compounds compete with EKM, EVMQ, ECO, ACM, and high ACN content nitrile mbbers. Big applications include automotive timing belts, blowout preventors, drill pipe protectors, and numerous oil and fuel pump components. 

A toller may need to use resources outside their company to measure physical properties, conduct safety or other testing, engineer changes to piping or other facilities and equipment. This need frequently occurs for products in the initial development or commercialization stage. The toller should maintain confidentiality agreements with their suppliers and subcontractors commensurate with the proprietary nature of their client companies processes. Provision to allow disclosure of information to third parties should be addressed in the contract between the toller and the client. It may be structured so that the client must approve the toller s release of information to third parties. 

Natural gas must always be contained in appropriate pipes or vessels and precautions taken to ensure that leakage cannot occur. If a gas leak does occur, the main gas supply should be shut off, the area ventilated and the gas supplier informed. Electrical switches should not be turned on or off, portable electrical appliances including handheld torches should not be operated and all other possible sources of ignition removed or rendered inoperable and the affected area ventilated. In circumstances of excessive leakage, the building should be evacuated. 

Sometimes a set of items such as all the process control instruments or all piping is lumped together, and a number of suppliers are asked to bid on this package. At other times the company may have a contract with, say, a pump manufacturer that guarantees the company will receive a specified discount on the cost of all pumps, if it purchases more than a certain number per year. Then the pumps would be purchased from this vendor. There are even instances where the company may forbid the purchase of items from a given vendor. For instance, one company found that the pumps it purchased from a particular manufacturer cost approximately 5 times as much to maintain as the other pumps it had performing similar tasks. The company refused to buy any more pumps from that manufacturer. 

Do you require suppliers to provide documentation that all piping and appurtenances are certified "for chlorine service" or "for sulfur dioxide service" by the manufacturer ... 

Packed-Cland Joints These joints (Fig. 10-138) require no special end preparation of pipe but do require careful control of the diameter of the pipe. Thus the supplier of the pipe should be notified when packed-gland joints are to be used. Cast- and ductile-iron pipe, fittings, and valves are available with the bell cast on one or more ends. Glands, bolts, and gaskets are shipped with the pipe. Couplings equipped with packed j ands at each end, known as Dresser couplings, are available in several metals. The joints can be assembled with small wrenches and unskilled labor, in limited space, and if necessary, under water. 

Aluminum pipe schedules conform to those in Table 10-22. Consult suppliers for available sizes and schedules. 

Metal ion concentrations in water vary enormously across Europe. The water hardness of the market area can be found fairly easily from water companies hardness maps. Some data on transition metal ion limits and measurements can also be found from water quality data, but even these might not be enough to determine what the consumer uses. For instance, metal ions can dissolve out of pipework into domestic water after it has left the water supplier s plant. Copper is commonly leached out of copper pipes and this can be more acute after leaving for even as short a time as overnight, and so while typical copper levels are much less than 1 ppm [33] there have been measurements up to 5 ppm [34] from domestic taps in European households. 

The calculation of safety valves is regulated by the AD-Merkblatt A2, Edition September 1998, and must be used by plant suppliers. Included in this regulation is the set-up and the piping system for the safety valves, also. The support of the safety valves must consider the potentially enormous reaction forces. 

Adequate information must be available for installed costs of piping and pumping equipment. Although suppliers quotations are desirable, published correlations may be adequate. Some data and references to other published sources ate given in Chapter 20. A simplification in locating the optimum usually is permissible by ignoring the costs of pumps and drivers since they are essentially insensitive to pipe diameter near the optimum value. This fact is clear in Example 6.8 for instance and in the examples worked out by Happel and Jordan (Chemical Process Economics, Dekkcr, New York, 1975). 

Nonintegral pipe attachments are used widely for support purposes. They are favored for their simplicity in attachment to the pipe wall, freedom in location, and availability as standardized stock items from many suppliers (see Fig. 6). 

Storage and handling of the propellants (CFCs and HFAs), types of filters, transfer piping, and storage tanks should be standardized. Any observations of the appearance of the propellants should be recorded. The supplier s specifications should be reviewed. 

E 2] [R 17] The process analyzer and sample-handling system MPC introduced by Swagelok also offers the possibility of performing as a process toolkit. Sensors are already supplied (see Section 4.11.2). Micro reactors are still not available from the supplier but a software configurator exists with pipe layout functions [23]. 

All piping and equipment for use with silane must be leak-proof. Leaks will be indicated by flames. Excess may be disposed of by controlled burning. Alternatively, seal cylinders and return to suppliers.2... 

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