ASME B16.39:2009 pdf download

ASME B16.39:2009 pdf download Malleable lron ThreadedPipe Unions Classes 150,250, and 300
1 sCOPE1.1 General
This Standard covers threaded malleable iron unions,Classes 150,250,and 300. It also contains provisions forusing steel for NPS 1/g unions. This Standard includes(a) design
(b) pressure-temperature ratings
(c) size
(d) marking
(e) materials
(f) joints and seats
(g)threads
(h) hydrostatic strength
(i) tensile strength
(j) air pressure test
(k) sampling
l)coatings
(m) dimensions
Mandatory Appendix 1 provides tables in U.s.Customary units.
1.2 References
Standards and specifications adopted by reference inthis Standard are shown in Mandatory Appendix I,which is part of this Standard.It is not considered practi-cal to identify the specific edition of each referencedstandard and specification in the text, when referenced.Instead, the specific editions of the referenced standardsand specifications are listed in Mandatory Appendix II.1.3 Quality Systems
Nonmandatory requirements relating to the fittingmanufacturer’s quality system programs are describedin Nonmandatory Appendix A.
1.4Relevant Units
This Standard states values in both Sl (metric) andU.S. Customary units. These systems of units are to beregarded separately. Within the text, the U.S.Customaryunits are shown in parentheses or in separate tables.The values stated in each table are not exact equivalents;therefore, it is required that each system of units be usedindependently of the other. Combining values from thetwo systems may constitute nonconformance with theStandard.
1.5 Service Conditions
Criteria for selection of materials suitable for particu-lar fluid service are not within the scope of this Standard.1.6 Convention
For the purpose of determining conformance with thisStandard, the convention for fixing significant digitswhere limits, maximum and minimum values are speci-fied, shall be rounded as defined in ASTM E 29.Thisrequires that an observed or calculated value shall berounded off to the nearest unit in the last right-handdigit used for expressing the limit. Decimal valuesand tolerance do not imply a particular method ofmeasurement.
1.7 Denotation
1.7.1 Pressure Rating Designation.Class, followedby a dimensionless number, is the designation forpressure-temperature ratings as follows:
Class150250300
1.7.2 Size. NPS, followed by a dimensionless num-ber, is the designation for nominal fitting size. NPS isrelated to the reference nominal diameter,DN, used ininternational standards. The relationship is, typically, asfollows:
2DESIGN
The complete union shall consist of a tail or male part,a head or female part, and a union nut. The type of jointmay be ball-to-cone, ball-to-ball, or ball-and-socket withmetal-to-metal seating surfaces of iron, copper, or cop-per alloy.The threaded ends shall be male or femalepipe threads.The head or female part may be furnishedas a coupling, an elbow, or a tee.
3PRESSURE-TEMPERATURE RATINGS
(a)Pressure-temperature ratings are shown in Table 1and Table I-1.
(b) Unions with copper or copper alloy seats are notintended for use where temperature exceeds 232C(450°F).
(c) All ratings are independent of the contained fluidand are the maximum pressures at the tabulated temper-atures. Intermediate ratings may be obtained by linearinterpolation between the temperatures shown.
(d)The temperatures shown for the correspondingpressure rating shall be the material temperature of thepressure-retaining structure. It may be assumed that thematerial temperature is the same as the fluid tempera-ture.Use of a pressure rating at a material temperatureother than that of the contained fluid is the responsibilityof the user and subject to the requirements of any appli-cable code.
4SIZE
4.1 Nominal Pipe Size
As applied in this Standard,the use of the phrase”nominal pipe size”or the designation NPS foilowedby a dimensionless number is for the purpose of identi-fying the end connection of unions. The number is notnecessarily the same as the fitting inside diameter.The connecting pipe dimension can be found inASME B36.10M.
5MARKING
Unions shall be marked on the nut with the manufac-turer’s name or trademark and nominal pressure class except on bar stock unions, where marking is impracti-cal. Additional markings permitted by MSs SP-25 maybe used.
6MATERIALS
(a)The mechanical properties of the malleable ironcastings shall be at least equal to those specified in ASTMA 197.
(b) Steel bar stock having a yield strength of not lessthan 207 MPa(30 ksi) may be substituted for malleableiron in NPs 1/ unions.
(c) Insert rings may be of suitable copper or copperalloy. Where copper alloy seats are furnished, either thehead or tail part of unions produced from bar stock maybe solid copper alloy.Such parts must meet the tensilestrength requirements listed in Table 2 and Table 1-2.
7 JOINTS AND SEATS
Inserts shall be secured into the ends to become apermanent part of them with no signs of cracking.inserted seat rings shall be of sufficient width to allowample bearing for the seating of the male end.
THREADING OF PIPE ENDS
8.1 Types of Threads
Pipe ends of head and tail parts shall be threaded withtaper pipe threads (ASME B1.20.1) except that NPS 1/sunions made from bar stock may have NPSC internalstraight pipe threads.
8.2 Tolerances
The variation in taper threading shall be limited toone turn large and one turn small from the gaging faceof the ring and gaging notch on the plug when usingworking gages.