A, the old trap type selection standard problems: hon fung think on the royal chemical industrial company is located in Huddersfield and Grangemouth ( England) Industrial plant of steam trap performance for seven years of monitoring and experiment, the level of the two producers laboratory performance and the fresh steam trap loss monitoring and experiment on the basis of the royal chemical industry company finally to its 'engineering design of the guidance about the content of trap selection changes. The changed new instructions included trap selection table. Old trap selection standards exist many drawbacks, the most obvious is that it is no mention of hydrophobic device types and hydrophobic method. The selected trap often does not match with the actual load. Especially, thermodynamic disc steam trap ( The basis of old type selection standard) Especially by people mistaken for universal trap shop personnel. Experiment reveals that the old trap selection standard has a lot of problems: 1, the director of steam trap life is too short. 2, trap performance has failed, and the actual load selection does not match. 3, the most widely used as a general thermodynamic disc type steam trap, the energy saving effects of the worst, and compared with inverted bucket steam trap, the life is very short. 4, bimetallic strip action easy trap is not stable. Second, trap selection techniques: the changed new 'guidance includes trap selection table. Trap selection skills: 1, the inverted bucket steam trap, as all the process load and steam mains trap of choice, that is, all need to steam the occasion of hydrophobic. 2, floating ball thermal static trap: used in the process of hydrophobic, especially in the control load 3. Less than 5 kg ( 50psig） Applications or air content is high, the installation of the occasion of inverted bucket steam trap has a problem. 3, equilibrium pressure steam trap: used for heating or heating system is not important. 4, bimetallic strip thermal static trap: used for heat tracing pipeline or heating system working condition of low temperature and frost prevention. This type of trap can maximize the use of condensate in the sensible heat or to prevent overheating. The body as a whole stainless steel. 5, thermodynamic disc steam trap: as long as in the previous experience has shown its good performance, can be used as an alternative to inverted bucket steam trap, under pressure to 17 kilograms of supervisor and with heat pipe steam limited use, or as a replacement for higher steam pressure. Because of its low energy efficiency, short service life, is not recommended, Moreover, in Huddersfield and Grangemouth factory are not allowed to use) 。 6, in the heat requirement is not high, with hot static trap instead of thermodynamic disc steam trap can improve the effect of energy saving, at the same time guarantee the service life. 7, machinery trap ( The inverted bucket and float trap) No matter big or small load in the condensate load cases can ensure the steam contains no condensed water, and hot static trap accumulation when load increases the condensate.