Document zogagdKVLG11z58YyQyYdOj2n

$64 CHAPTER 26 1950. Guide i5j^b a taper,Qf;l:'in 16 measured on the diameter of the.pipe so as to. secure a tight joint. The number of threads per .inch varies with the pipe size.' Threads for fittings are the same, except that it is regular practice to furnish straight tapped couplings for -Schedule "40 pipe 2 in. and smaller. For steam pressures in excess of 25 psi, it is recommended that taper-tapped couplings be used to obtain a tight joint. These may be secured by ordering line pipe* which is used for oil pipings the couplings of which are provided with taper-tapped threads and. may"be used with regular mill-threaded standard weight pipe. . Thread, lengths should be in accordance, with ASA B2.1. Right-hand threads are used unless-otherwise ordered. To facilitate drainage,' some elbows have'the thread tapped at an .angle-to provide a pitch of the connecting pipe of J ini to the foot: These elbows are \ tCOMWrjTilOWTUffiPftffnPg9 aARKU8a FITTINGS Fia. '2. Copras os Bbass Tubing Fittings known to the trade as pitch elbows and are commercially'available. AH threaded pipe joints should be made up with a thread paste suitable for.the service for which the pipe is to-be used. - ;: TYPES OF FITTINGS ^ '. Fittings for joining the separate lengths of pipe together.are made in a variety of forms, and are either screwed or flanged, the-, former being generally used, for the smaller, sizes of pipe, up-to. and including 3j in., and the latter for the larger>sizes, 4 in. and-above. (.Screwed. fittings of large size, as well as flanged fittings of small size, are also made and are used for.certain classes of work at the proper pressure. . The material used for fittings is generally cast-iron, but in addition to this, malleable-iron, steel and steel alloys are also used, as well as. various grades of brass or bronze. . The material to be used depends on the char acter of the service and the pressure. Malleable iron- fittings, .like .brass fittings, are cast with a round instead of a flat band or bead, or with no bead at all. Fittings are- designated as male or female, depending on whether the threads are on .the outside-,or inside,: respectively, >: Screwed galvanized -fittings are made according to, the,450 lb American Standard. Pipe.Fittings, Welding ,565 -Table 5. -AmebicaN STANDABD"DiMENsi6NSOF,ELBOW3,:TEEsj'CBOssES,.ANb45 Deo Elbows, Soldebed-Joint Fittings, ASA A40.3-1941. -j- - . Cast Brass6 Noional SOEB -. "Laying Length. Tee. EH, nnrl Cr069b Laying Length, EU With External Shoulder Laying. Length, 45 Deg ,31 "Laying Length. 45 Deg EH External -Shoulder Inride i. Diameter /. "of " Fittings, '; Min. - total Thickness* > Wrought Metal Boss or Metal Fzrrunu Thickness* Min.* 1..' . . h' . KX Vs.. XX V -- ' IX IX ' - Jw' -X Vi f- 2 - * IK IK 3 , IX 2 4 - -r 2M 5 3K 6 3K . i. ' n._~ J . Q_ / o ;T ' X Xe '-X X& X, Xs % - X> 5fi lXs X K i y X, ' = Xs , Xi % 0.31 0.43 0.54 0.78 - T.02 11.26 0.08 0.08 0109 0.10 0.11 0:12 IK K K ' 1:50 - 0.13 IK - % X .. A.98 0115 IK - K - K 2.46 .0117 IK X l 2.94 0.19 2K ; K : ik 3.42 0.20 2K % IK -3,90 0.22 m 4.87 0.28 -- IK 5.84 0.34 r;: _ 'T and R_ `E, Min. 0.048 0.048 0.054 0.060 0.066 0.072 0.078 0.090 0.102 0:114 0.120 0,132 0.168 0.204 01030 0.035 0.040 0.045 0.050 0.055 0.060 0.070 0.080 0.090 0.100 0.110 0.125 0.140 0.378 0.503 0.628 0.878 1.1285 1.3785 1.629 2.129 2.629 3.129 3.629 4.129 5.129 6.129 All-dimensions given in inches. * This size is the nominal bore of the tube. k These 'dimensions may be used for wrought-metal fittings as well as for cast-brass fittings at manu facturer's option. . L 0 This dimension.is the same as the inside diameter Class L tubing (American Standard Specifications for Copper Water Tube, AJ3.A. H23.1-1939 (AjS.TJf.B88). ^ Patterns shall be designed to produce body thicknesses given in the table. Metal fhiclmpaa at no point shall be less than SO per oent of the thicknesses given in the table.-' - 9 This dimension has the same thicknesses as'Type L tubing. - * These dimensions are minimum, but ;n every case the thickness of wrought fittings should be at least as heavy as the tubing with which it is to be used. ? '< .. Note 1:--Wrought fittings, as well as cast fittings, must be provided with, a shoulder or stop at the bottom end of socket. ' Note 2:--Street fittings with male ends are for use in Connection with Other fittings illustrated. As in the case of pipe, several weights- of fittings are manufactured. Recognized American"Standards for the various weights are as follows: ! Cast-iron pipe flanges and flanged fittings for 251b"(sizes 4 in. and larger), 125 lb, and 250 lb maximum Saturated" steam pressure,' ASA B16b2, B16a, and B16b, re spectively. --. ~ Malleable iron screwed fittings for 150 lb maximum saturated steam pressure. ASA B16c. .... - ;- . . ' Cast-iron screwed fittings for 125 and 250 lb maximum saturated steam pressure ASA B16d. - - . Steel flanged fittings fOr, 150 and 300 lb .maximum steam service pressure, ASA ,B16e. The allowable cold water working pressures for these standards vary from 43 lb for the 25 lb standard, to 500 lb for the 300 lb steel standard. War-standard ratings in effect'for-the' duration of the ejpergency per mitted higher ratings for certain sizes of the 125 lb cast-iron flanged