Traps purchase and selection recommended

In a seven-year monitoring and piloting of Trap performance at Royal Bank of the British Chemical Industry Industrial Estate in Huddersfield and Grangemouth (England), a first-class trap performance and fresh steam loss monitoring at two producer laboratories On the basis of the experiment and the experiment, Royal Chemical Industry Chemical Company finally modified the content of the trap selection in its "Engineering Design Guideline". The old selection criteria have a number of disadvantages, most notably the lack of mention of the type of hydrophobic device and the method of hydrophobicity. The chosen trap often does not match the actual load. In particular, thermodynamic disc traps, the foundations of the old selection criteria, were mistakenly considered as universal traps by people, especially shop floor personnel. As early as 1980, Grangemouth began monitoring trap performance as engineering maintainers complained about the short life of the steam trap. Two years later, the same monitoring was done at the Huddersfield plant. In the monitoring, the trap was first investigated, to understand the type of existing traps, and check the selection of load. At the same time also conducted a related test. The initial result is astonishing. Tests on 415 traps in a shop showed that 19% of the traps worked and 63% did not match the load. A survey of 132 steam traps in charge of supervisors showed that 42% of the traps worked. Inspection of the life of the trap also started in 1980 and has continued until now. Table 2-1 lists the average life span of various traps. To test the energy-saving benefits of various traps, fresh steam loss tests were carried out on the traps that are being used in the labs of both manufacturers. The test is carried out in the laboratory, ie at 20 ° C, still air. The experiment did not detect the heat loss of the trap body. Condensate load in the test is 10-20 kg / hr (22-44 lb / hr) common. The test results are summarized in Table 2-2. The most interesting thing about these two tables is that they are the most versatile, most widely used thermodynamic disk traps, which have the lowest energy savings and are extremely short-lived compared to inverted bucket traps. In the heat less demanding situations, the use of thermostatics to replace the thermodynamic disc traps will improve energy efficiency, while ensuring the service life. These experiments also revealed that mechanical traps (ie, inverted buckets and float traps) can ensure that steam does not contain condensed water, either at high condensate load or at low load, Easy to accumulate condensed water. In addition, bimetal traps easily unstable. After the change of the new "guidance" includes trap selection table. Valve Selection Recommended: inverted bucket traps: As the first choice for all process loads and steam main traps, that is, all need to steam hydrophobic occasions. Float Thermostatic Traps: For process hydrophobics, especially where control of loads up to 50 psi (35 kg) or applications with high air contents and installation of inverted bucket traps is problematic. Balanced Pressure Traps: Used as a non-critical heat tracing or heating system. Bimetal thermosyphon trap: for heat tracing or heating system low temperature or anti-frost conditions. This type of trap allows to maximize the use of sensible heat in the condensate or to prevent overheating of the product. The valve body is all stainless steel. Thermodynamic Disc Traps: As an alternative to inverted bucket traps, as long as previous experience proves to be of good performance, they are used as restricted on steam and heat tracing pipes under 17 kg, or as a replacement At higher vapor pressure. Not recommended because of its low energy efficiency and short lifetime (and not allowed at Huddersfield and Grangemouth).

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