1、ASTM D3140 90 m 0759530 OObO=lLB 3 U Designation:D 3140-90 AMERCAN SOClETY FOR TESTING AND MATERIALS 1916 Race SI,Phlladelphaa.Pa 19103 Reprmled lrom Ihe Annual Book 01 ASTM Slanderds.Copyright ASTM II not Wed in lhe current combmed index,wll appear m the nexl edltlon Standard Practice for Flaring P
2、olyolefin Pipe and Tubing This standard is issued under the fixed designation D 3140;the number immediately following the designation indicates the year of original adoption or,in the case ofrevision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscrip
3、t epsilon(6)indicates an editorial chanp since the last revision or reapproval.1.Scope 1.1 This practice covers general procedures for flaring polyolefin pipe and tubing for use in flare nut joints and fittings such as AWWA and other standard flare fittings.Pipe producers,fitting and tool manufactur
4、ers instructions and recommendations should be consulted in all applications.1.2 The techniques covered are applicable only to the flaring of polyolefin pipe and tubing products that are specifically recommended for such flaring-by the pipe or tubing manufacturer.1.3 The values stated in inch-pound
5、units are to be regarded as standard.The values shown in parentheses are for information only.1.4 This standard does not purport to address the safety problems associated with its-use.It is the.responsibility of whoever uses this standard to consult and establish appro-priate safety and health pract
6、ices and determine the applica-bility of regulatory limitations prior to-use.2.Significance and Use 2.1 The techniques described herein can be used in conjunction with the tool manufacturers specific recom-mendations to produce properly made flares in polyolefin pipe and tubing which in assembly wit
7、h an appropriate flare fitting,will make a strong pressure-tight joint,whether made in shop operations or in the field.Some skill and knowledge on the part of the operator is required to make a proper flare and joint.This skill can be obtained by practicing under the guidance of an operator experien
8、ced in the techniques or by following the instructions furnished by the manufacturers.3.Classification 3.1 Two methods of flaring are covered in this practice as follows:3.1.1 Cone Flaring,normally requiring the application of heat from an external source to soften the plastic for*forming.3.1.2 Spin
9、 Flaring,not requiring an external source of heat since mechanical flexing of the plastic material produces substantial frictional heating.3.1.2.1 Example:One or more tool projections are rotated and fed into the end of the pipe causing repeated mechanical flexing of the pipe wall and expanding it u
10、ntil the desired flare diameter has been obtained.3.2 Two types of flare are covered in this practice as follows:t This anctice is under the jurisdiction of ASTM Committee F-17 on Plastic Piping Systems and is the directresponsibility of Subcommittee F17.20 on Joining.Current edition approved July 2
11、7,1990.Published September 1990.Originally published as D 3140-72.Last previous edition D 3140-85.3.2.1 External Flares,consisting of the conventional flare made outside the flare nut and later pulled into the flare nut seat prior to assembly and makeup of the flare joint.3.2.2 Internal Flares,chara
12、cterized by the fact that the flare is formed within the flare nut in such a way that the rim of the flare is captive in a nut recess,preventing axial movement once the flare is completed.4.End Preparation 4.1 The end of the pipe or tubing to be flared shall be cut off clean and square to the axis,p
13、referably with a pipe or tubing cutter equipped with a sharp-edge wheel specially made for cutting polyoletin pipe or tubing.No cuts,scratches,dirt,or surface damage to either inside diameter or outside diameter are permitted on the pipe end to be flared.5,Methods 5.1 Cone Flaring:5.1.1 External Fla
14、re-After the pipe or tubing end has been prepared for flaring in accordance with section 4,the appropriate flare nut shall be slipped over the end of the pipe or tubing.Heat shall be applied indirectly to the outside of the pipe or tubing from a suitable source of heat,provided that no open flame is
15、 allowed to impinge on the plastic material,The plastic shall not be permitted to smoke or ignite.The heat source shall be moved about the circumfer-ence with a constant motion to prevent local overheating and promote uniform heating.When the outer end of the pipe begins to curl and the heated surfa
16、ce appears to sweat,the heat source is removed and a flaring tool specifically designed for the purpose is immediately applied to form the flare while the pipe is hot.The finished flare,after cooling and the tool has been removed,shall be of a diameter slightly larger(0.8 to 1.6 mm(V32 to/I6 in.)than the diameter of the flare nut threads,requiring some force to be pulled into the flare nut seat.Since the finished flare diameter is directly dependent upon the amount of tool travel and material al
