【正文】 to check the tightness of joint surfaces between valve seat and valve core, valve cover and padding chamber. Water pressure, which times more than pressure marked on nameplate, should be applied in the tightness test of valve. No less than 10% (at least 1 vale) in the same batch (the same manufacturer, specification and model) must be checked by sampling for tightness test for low pressure valve。C when bending alloy steel pipe, and forced air cooling should be used. Normalization and temper treatment is required after bend is finished. When bending new type of steel pipe, test must be done for the Max. deformation of back arc of steel pipe, and bending process can only be established to bend the pipe after it had been confirmed that no defects such as intercrystalline fracture exists. Check by sampling (sample can be obtain at the place of bending section) is required after heat treatment is ended for the initial use of new steel type, or mon steel type which heat treatment specification had been changed, to obtain data specified in item (2), (3) and (4) in article of this code. External and internal surface must be cleaned after the preparation of bend pipe. Data such as out of roundness, wave degree, angle deviation and reducing value of wall thickness must be in concordance with following rules after the preparation of bend pipe: Out of roundness of bend section should not be more than: 5% for high pressure pipe。 miter elbow (c)45176。 Other places: less than 3% outer diameter for high pressure pipe。 Correct assembly, flexible action, and the indicating position of opening indicator should be accurate。 and its hardness should be less than the flange39。 Thermal meter pipes。s Republic of China The Notification of Issuing the Electric Power Trade Standard The Code of Erection and Acceptance for Electric Power Construction (Piping section) Electric Power Technology [1994] All electric power administrations, all electric power bureau, electric power planning institutes, and electric power construction institutes of provinces (municipalities directly under the Central Government, autonomous regions) and Water and Electric Power Press: For adapting the development of electric power industrial technology and insuring the erection quality of pipes of thermal Power plant, the Code of Erection and Acceptance for Electric Power Construction (piping section) DJ 5679 issued in 1979 had been revised by the ministry. The new code should be looked upon as electric power trade standard and the code number is DL 503194. The standard is approved and issued now and will be go into effect from Oct.!, 1994 and the older version should be abolished at the same time. Any question in the performing should be notified the Construction Cooperating Department of the ministry please. Apr. 9,1994 2 Contents General rules ...................................................................................................................................................... 3 Glossary.............................................................................................................................................................. 5 Checking of pipes, pipe fittings, pipe accessories and valves ............................................................................. 5 General regulations ..................................................................................................................................... 5 Checking of pies ......................................................................................................................................... 5 Checking of pipe fittings ............................................................................................................................. 6 Checking of pipe accessories......................................................................................................................... 6 Checking of valves ....................................................................................................................................... 6 Preparation of pipes, pipe fittings and pipe accessories...................................................................................... 7 General regulations....................................................................................................................................... 7 Elbow pipe ................................................................................................................................................. 7 Processing of reel pipes, pipe fittings and pipe accessories ............................................................................. 8 Processing of supporting and suspending bracket ......................................................................................... 11 Installation of pipes.......................................................................................................................................... 12 General regulations..................................................................................................................................... 12 I Installation of high pressure pipe ................................................................................................................ 13 Installation of medium and low pressure pipe .............................................................................................. 14 Installation of water drainage pipe ............................................................................................................. 15 Installation of valve and flange .................................................................................................................. 15 Installation of supporting and suspending bracket .......................