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888* CHAPTER 58 1965 Guide And Data'Boole: Table 13 .... Dimensions of Malleable-90-Deg-*Bbowsi !` o'Toblel 4 .... Dimensions of Cast-Brass Solder-Joint Elbows, Tees, Crosses, and 45-Deg Elbows (Sfraight:Sizes,---l50 Lb)s--- -Tees, and 45-Deg Bbows ISfroigijf Sm) cnc c to c to c c to c e to r e to r - , FnxS American SOrniaH far UaUrabtc-lrr. Scinrti Fitting*. ISCLb.'45A BMX-ltU. All cimenaioo siren in inchru -* Standard Water Tab* Sic* laying . ' tang**? Tom and Elbow Center fo Ex ternal Shotdder 9O*O0 Sllwl Elbow K Laying Center to Ex -t*ngA ternal Shoulder 45-Deg '' 45-0*0 Str*f Elbow Bbow Q -K , K: '. k; i IK }X ` 2 2K 3 zx- X He He Hi; X X I IK iK- ; IK 2 H: Ke Xt % X. l IK IK IK IK Ms Ke' K, Ke He X. Ke H X 'X Xi Ke Ke Ke X X 4 5 .6 ...8 3K . 3h \m -2K `Ke IHe IK .2M From American Standard for Cott-Briu* SeLifr-Jvinl FitUngt, ASA B16.1S- 1S6S. All dinmiw) given in incto. * Not for vwiv^i fittisgeCoasult n..nwi^iw.for Hifiwwiiw,. 3.. Welding 'Ends: Available in steel only. Generally employed for high-temperature, high-pressure work. -Difficult to disassem Malleable iron, which is a cast.iron heat-treated to provide ble in a. welded line. This type includes butt-welding or,socket* welding^ See TablesiO ana 12for'sbe of fittings available in ` i some ductility, is used to some extent, primarily in place of each class.' The valves are made in the'same range. ' ' cast iron. '4.1 Brazing'Endi: These ends are-available on brass' valves. j'' Steel is used either in the cast or forged state. For corrosive The ends have a special shape to facilitate use of brazing alloys. service, alloy and stainless steel are used. Steel is used for high These .valves are-used for (higher temperatures than solder aid valves^ - f % , .. . . - ---. 5.- Solder. End*: For use with copper tube in plumbing, heatihg,"ahd ur'conditioiung. Should not be used at high' temperatures. . temperature; high-pressure work. Steel is the only valve ma.iterial that can stand appreciable .expansion stresses. .1: The characteristics of valves restrict their use. The five main uses for valves are listed below: ' 6. Flared End*: For use with light-wall tubing, either metal ' Stopping Jlotr.-.The most general use'for valves. Gate or'plastic/and for sizCs 2 in. and below.1 A flaring tool flares the ; valves are generally used for this purpose; except in refrigeration tube end,-'and a ring:-nut pulls the:flared.tubing up against a * piping. The cate valve operates by moving & disc at right angles seat po tne valve. This makes a.lap. joint. to the path of.the fluid. The fluid nows straight through the valve, 7. Hvb End*: Generally used for water supply-and sewage . ... therefore, a gate valve offers the minimum resistance when it is piping. Hits type joint is used with cast-iron pipe. The joint ts fully open. The gate is moved by a stem screw attached to the a socket type, made by inserting the pipe in the hub, then caulk handle. Gate valves are poor regulators because, at nearly closed ing with oakum. After being caulked, the joint is sealed with position (where best regulation is obtained), the fluid velocity molten lead. cr'-V either.causes vibration and noise or-tends to erode tho HW. ' 2. -Throttlingflow: This`is generally accomplished by globe or Valves are'madeof brass, !iron, steel, and to some`.extent malleable iron. Brass-should not be'used'for^wdrk'iequiring temperatures above 550 F. The brass used in-valves is similar angle'}valves. .These, valves,cause the fluid to change direction,, and consequently,' offer"considerable' fluid resistance jerven'when in:the open position! Both'the'globe and'ahgle valvee'pperate by ringing a plug into, a fitted seat. The angle*valve'is similar to to'that usedinbrafis pipe and contains some tin and'lead as the globe valve except that the outlet face is at an angle of 90 deg welTas'copper'and'kinc. ' '' Cast iron is generally provided in some alloyed state, espe cially"in'the l^ge^:'sizes. .Cast iron'alone,is nojt suitable for from the.inlet face. Anlangle valve takes the, place .of. a globe' valve and ah elbow. , .` 3. Cheeking fleno: Preventing'back "flow1 is' called checking, hence, a-check valveused.'-Hie basic prinaple'of! all check .servioe'(above 450 F)i valves, is-that a reversal of flow. will,.close..tke.valve. Gieck Pipe, Tube, and Fittings 889 valves are either firing cheek or lift cheek. With a swing check, the fluid presses' on a hinged flap. If the flow stops or reverses, the flap swings down ana seats itself to close the valve. A lift fhflt operates similarly, except that the flap is replaced by a plug is lifted, through guides, by the force of the fluid flow. The fluid changes direction of flow, as in a globe valve, and transmits a vertical thrust. If the flow stops, gravity pulls the plug downward and closes the valve. A reversal of flow will close the valve. Spring-loaded check valves are also widely used in refrigeration systems. 'i * Two other types of valves are the relief valve and the pres sure regulating valve. Relief valves ore usually spring loaded in.order that some predetermined pressure can'force'the valve to open and relieve the pressure. Pressure regulators are used to,reduce a high incoming pressure to a required service pressure but may also be used to control the inlet pressure. These valves are designed to eliminate a fluctuation in the incoming pressure and thereby maintain, a . steady,. lower service' pressure (see. Chapter 8, 1964 .Guide And., Data Book). WELDING. Erection of piping in heating and ventilating installations by means of fusion welding has been commonly accepted in' the past few yearsas an alternate method to the screwed and flanged joint. 'Since the question of economy- of welding versus the use of screwed and flanged fittings is dependent on the individual job, the use of welding is generally recom mended on the basis of: greatly reduced cost of maintenance and repair, reduced weight resulting from the use of a lighter- weight pipe, or increased economy in pipe insulation, hang ers, and supports, rather than on any economy that might be effected in actual erection. by welding on low to medium pressure hearing jobs. Fusion welding, commonly-used in erection of piping, is defined as the process of joining metal parts.in the molten, or molten and vapor states, without the application'of me chanical pressure or blows. Fusion welding-embraces gas welding and electric are welding, both of which are commonly used to produce acceptable welds. ;WeIding processes and pro cedures are described in various publications.* Welding application requires the same basic knowledge of design as do the other types of assembly, but, in addition,it re quires an extensive knowledge of welding principles, particu larly the welding , qualities of-.metal and its reaction to ex tremely high temperatures. The ability to select-and use the proper welding rods is important. This requirement ap plies equally to employer and employee, with.the employer accepting all of the responsibility. Thus the employer should use good judgement in selecting his welding mechanics, pro vide them with first-class equipment and tools, arrange for their training and use of acceptable workmanship standards, and, at regular intervals, subject their work to prescribed tests. . Rules for fusion-welding of pipe joints, the. qualification of welding operators,,welding procedures, and testing are-con tained in the Standard Manual on Pipe Welding, and in pub lications of other groups.1,V1 In general, the wall thickness and chemical analysis of the pipe are the governing factors,- not the working pressure. There are a number of safety codes which govern the installation of welded piping.in many cities, and states. A complete line of manufactured steel-welding-fittings is now available, and a dimensional standard h been prepared according to the procedure of the American Standards Assock ation (see Table 10), to unify, heretofore divergent dimensions for the same type welding fittings produced by different manu facturers. Standard dimensions for steel butt-welding elbows Table .. ..Dimensions of.Cost-Brass c Solder-Joint-Couplings .< STRAIGHT REDUCING ^_ ECCENTRIC Standard Water Tab* Sic* laying UngS" -M . Standard Water Tub* . Sis* toying Ungih* N Standard Water Tub* , Sis* toying langSt* W xK; Ke ' K * K Ke ' Hi K ' -J x- He1 I x; X " X ' 1 x X `Ke xX :K IK *1 'K' lK x i- ' :r X - '' K V.; lXx-X : * " IK x H ; X 1 K IK x iK H ' IK* IK- ' 'Hi ' IK vK IK x I K ,IK * i *K. IK X-' IK x K He 2 xlK IK Hi2 2 xlK K 2. -x IK `Ke 2K . .,3 - , 3K. - Keen 2 . Kei 2 .. K 2 x IK x1 xX ' 2K x2.:- IKe X 3: X2K IK K 3 x2 IKe : 4 K 2Kx2 Ke 4 x 3 - r-21 - `I 5 K 2KxlK Ke X; .6 K 2K * 1K` 8 X 2K*i X X3 x2K . .. 3 x2 H:. 4 x3 , Hi. ' - \ 4 x2K 1H>* 4 x2 ` IKe ` a . x 4 8 ifi ! IKe = IK *. ' From .AmcrKSn Slenijnri far Gut-Brow ScUer-Joint Fittingt.^ASA BIS.1S1983. All dimemioTM given to Ineheo. * * Not stondirdlttd M tmit*kCfittisp, Go&oalt --* "-^rtnrtrfar dinovm. and tees are given in Table 10..Dimensions for eccentric and concentric reducers, caps, and lapped-joint stub ends are not shown in Table 10, but are included in the standard.. - Steel butt-welding fittings have .beveled ends. For; wall thicknesses less than A in., the bevel may be either 37L deg or'cut square. For wall thickness,of, fa in. to and; including I in. the.beyelis 37k deg. For walls larger,,than | in. but-not greater than.l} in^-the bevel is U-ehaped,.with,a.slope..of 20 deg above the A in- radius fillet. For walls greater than l}'in., the welding ends are prepared as agreed between the manufacturer and the purchaser.' . ... flange fittings may be welded from sires | to 24 in., in clusive. "-1- 1 *' "'V;/ 1 Socket-welding'-fittings "als6'!are commercially `available. These fittings have a machined recess for;mserting ihe-pipe which is attached by a fillet wjeld between the pipe wall and socket end. Use of socket-welding fittings generally is re-.