Pipe manufacture

Tables 4—6 Ust ASTM methods used for the characterization of PB and PMP. A number of specialized methods were developed for testing particular articles manufactured from polyolefins several of these determine the performance of PB and PMP film, including the measurement of the film s dart impact strength and tear strength. Dart impact strength is measured by dropping a heavy dart with a round tip on a stretched film. Tear resistance, which reflects the film s resistance to tear propagation, is measured with the Ehnendorf tear tester. Two values for the tear strength are usually reported, one in the machine dkection of the film and the other in the transverse dkection. Pipes manufactured from PB are tested by pressurizing them internally with water the time-to-burst failure is determined at various temperatures (46). The standard test method for haze and luminous transmittance (ASTM D1003) is used for the measurement of PMP optical characteristics.

NOTE Consult pipe manufacturer for recommended hanger spacing for the specific RTR pipe being used. Tabulated values are based on a specific gravity of 1.25 for the contents of the pipe. To convert feet to meters, multiply by 0.3048. 

Examination and Inspection The code differentiates between examination and inspection. Examination applies to quality-control functions performed by personnel of the piping manufacturer, fabricator, or erector. Inspection applies to fiinctions performed for the owner by the authorized inspector. 

Metal industries use substantial quantities of water in processes such as metal finishing and galvanized pipe manufacturing in order to produce corrosion-resistant products. Effluent wastewaters... 

TREATMENT OF WASTEWATER FROM ACID PICKLING TANKS IN A GALVANIZED PIPE MANUFACTURING FACTORY USING SULFURIC ACID... 

The initial evaluation showed that utilizing fiber-reinforced polymer (FRP) for pipelines is a feasible alternative to steel pipelines with regard to performance and cost [35]. From the cost analysis, an FRP pipe is quite attractive, especially in the regional or distributed service. Currently, spoolable piping manufacturers could install a composite pipeline for serving a 100,000 population for a cost of 250,000-500,000/mi. (does not include the cost for right-of-way), which is well below the DOE s capital cost target in 2017 of 800,000/mi. [35]. From this estimate and cost analyses, it is seen that FRP pipe economics is very attractive, especially for the distribution service. 

For use under this Code, the heat treatment requirements for pipe manufactured to A 671, A 672, and A 691 shall be as required by para. GR-3.6 for the particular material being used. 

Liner types available are suitable for a wide variety of chemical services, including acids, alkalies, and various solvents. All liners are permeable to some degree, and manufacturers use various methods to vent gas out of the interspace between the liner and casing. All plastics are subject to environmental stress cracking (ESC). ESC can occur even when the liner is chemically resistant to the service. Lined pipe manufacturers should always be consulted regarding liner selections and service apph-cations. Also consult manufacturers regarding vacuum service limits. 

Fig. 8.7. Effects of dynamic abrasion hardness testing of polyester pipes manufactured by Hoganas AB, sand-filled and inorganic fibre-reinforced.

As the plastic exits the die it is cooled on a conveyer. In addition to round pipe, extrusion lends itself to other shapes that are long and continuous, such as window moldings. Top companies in plastic pipe manufacture include Royal Group, Inc., J-M Manufacturing (doing business as JM Eagle) and CertainTeed. 

Electric resistance weld pipe manufacturing process.114... 

International Pipe Association s Voluntary Standard for Induction Bending of Pipe. Manufacturers Standardization Society of the Valve and Fittings Industry, Inc., Vienna, VA. 

Conventional poly(vinyl chloride) (PVC) batch preparation in which the dry materials are blended in a heated mixer and then cooled in a cooler mixer, was compared with the double batching preparation process. In this process, twice the required additives are added to the PVC, blended in the hot mixer, and the balance of the PVC then added to the mixed materials in the cooler mixer. This reduces the overall energy requirements. Rigid PVC for pipe manufacture was processed by both methods, and assessed by studying the rheological and physical properties and extrudability. Material of acceptable quality and pipe to the required standards were produced by the double batching process, with enhanced productivity and cost savings on power and labour. 4 refs. INDIA... 

Tests conducted for the Drinking Water Inspectorate show that some PVC pipes cause breaches of a new standard for lead due to be introduced in 2003. The failures are due to the use of lead salts to stabilise the plastic, and the DWI has warned pipe manufacturers that they must reformulate their products. 

Using redox potentials, explain the frequent occurrence of perforations in domestic hot tap water pipes manufactured from galvanized steel. 

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