1、February 2009DEUTSCHE NORM Translation by DIN-Sprachendienst.English price group 5No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (D
2、IN-Normen).ICS 23.040.01!$XyI“1538638www.din.deDDIN 2430-3Piping for pigging systems Part 3: Trial pigging (prior to commissioning)Rohrleitungen fr Molchanlagen Teil 3: Prfungen vor InbetriebnahmeSupersedesDIN 2430-3:2002-11www.beuth.deDocument comprises 5 pagesIn case of doubt, the German-language
3、original should be consulted as the authoritative text.DIN 2430-3:2009-02 2 Contents Page Foreword. 3 1 Scope . 4 2 Preliminary checks and inspections. 4 3 Trial pigging 4 3.1 General. 4 3.2 Liquid medium 4 3.3 Gaseous medium 5 3.4 Evaluation 5 4 Safety information 5 DIN 2430-3:2009-02 3 Foreword Th
4、is standard has been prepared by Technical Committee NA 082-00-03 AA Molchbare industrielle Rohr-leitungen of the Normenausschuss Rohrleitungen und Dampfkesselanlagen (Piping and Boiler Plant Standards Committee). The DIN 2430 series of standards comprises: Part 1: Straight pipes and elbows Part 2:
5、Pipe joints Part 3: Trial pigging (prior to commissioning) Amendments This standard differs from DIN 2430-3:2002-11 as follows: a) Clause 3.4 “Evaluation” has been modified. Previous editions DIN 2430-3: 1924-09, 1929-12, 2002-11 DIN 2430-3:2009-02 4 1 Scope This standard deals with the trial piggin
6、g, prior to commissioning, of piping systems. It describes two methods of trial pigging which serve to check the quality of the piggable components of the system. 2 Preliminary checks and inspections Prior to trial pigging the following shall be carried out: checking the installed piping system for
7、conformity with the DIN 2430 standards series; preliminary cleaning of piping system by purging; inspection of piping system for external defects; checking the pipe fixing elements for adequate resistance to the dynamic loads induced during pigging; inspection of piping system for internal defects u
8、sing an intelligent pig or a video camera; function testing of valves; pressure and leaktightness test in accordance with relevant codes of practice; checking the pig with respect to its type, dimensions, material and surface finish, documenting the results. Trial pigging shall be carried out using
9、the same pig type as is used in service. 3 Trial pigging 3.1 General Trial pigging shall be carried out to obtain an indication of the quality of pipes, pipe bends and welds as well as of the proper functioning of valves. Trial pigging also serves to detect and localize defects on pipes, pipe bends,
10、 joints, valves and welds. There are two methods of trial pigging, one using a liquid (see 3.2) and one using a gaseous (see 3.3) propelling medium. In order to facilitate pigging operations, several litres of an antiseize agent (preferably the same product as is used in service) shall be introduced
11、 into the system in front of the pig to prevent seizure. 3.2 Liquid medium The pig shall be run through the pipe using a liquid propelling medium, at a constant mass flow and at a speed of about 0,1 m/s. Care should be taken to prevent an air cushion forming between the pig and the medium. The perfo
12、rmance of the pigging system shall be documented, recording the fluid pressure during pigging operations in a pressure/time diagram. When using this method, the location of imperfections can be established with adequate accuracy by calculation, based on the quantity of medium used and the running ti
13、me of the pig. DIN 2430-3:2009-02 5 3.3 Gaseous medium The pig shall be run through the pipe using a gaseous propelling medium, at an average speed of about 1 m/s (pipe length/total running time). In order to facilitate the pigging operation, several litres of an antiseize agent shall be introduced
14、into the system. The performance of the pigging system shall be documented, recording the fluid pressure during pigging operations in a pressure/time diagram. This method does not permit imperfections to be exactly localized. It is, however, a simple and rapid method for assessing the general condit
15、ion of the system. Should any defect be discovered, it can be localized by additional trial pigging using a liquid medium. 3.4 Evaluation The results of trial pigging are highly dependent on the method, the pig and the antiseize agent used and require qualitative evaluation of the pressure/time diag
16、ram. A reliable assessment can only be made by comparing the results with those obtained from a pressure/time diagram of a reference piping system comprising the same elements as the system under test. Peak pressures during trial pigging higher than those in the reference system are indicative of de
17、fects in the piping system (e.g. pipe bends with constricted bore, weld sagging, incorrect valve setting). Other imperfections may be detected indirectly by inspecting the pig surface. This may show signs of wear and other defects. 4 Safety information The gas at the back of the pig may be at a high
18、 pressure. Since this constitutes an extreme risk, the following shall be observed: It shall be ensured that only suitable valves are used when the pig is changed. The piping system shall be completely relieved before the pig is introduced or withdrawn. The relevant safety instructions of the manufacturer shall be observed.
