Piping Pointers for Industrial Maintenance Men (sound)

[Music] in every industrial plant where piping is used safe and serviceable maintenance of valves and fittings is indispensable the purpose of piping pointers is to make available to industrial maintenance men the Practical information which crane the world's largest manufacturer of valves and fittings has developed in its more than 88 years of experience there are always young men starting to learn the essential jobs of industry but in emergencies it's sometimes necessary for a great many men to learn quickly how to assume responsibilities they've never faced before well piping pointers is intended to help such men and to refresh the memories of others who may have forgotten some of the tricks of the trade due to infrequent use of them in order to review these points as briefly and clearly as possible we're going to use two methods of study this textbook and actual demonstration both here and on the job now in every trade certain words are used with special meaning and it isn't always the meaning you'd expect there are a good many special words and special uses of words that you'll need to understand before you can handle piping intelligently so let's start making sure we all speak the same language brass and iron materials are commonly described as standard and extra heavy these terms indicate there are service limitations standard for example generally means suited for steam working pressures up to 125 lb extra heavy means suited to steam working pressures up to 250 lbs steel materials on the other hand are usually referred to by pressure classifications such as 150 lb 300 lb 600 lb and so on materials are also identified according to the types of end connections for which they are suited screwed end refers to Valves and fittings having either threaded male ends or tapped female ends these are not often used with pipe over 6 in in diameter because of the extreme difficulty in making them up flanged end refers to valves and fittings which are designed to be attached to pipe or equipment with bolted connections and Welding end implies welding to the connecting pipe this can be done either by butt welding or socket welding the difference is in the ends to be welded butt welding fittings and valves have have the ends beveled fittings designed for socket welding are shaped so as to slip over the pipe in either case the ends are fitted together and then welded in place another type of end connection common to copper and brass fittings is the solder joint end here the socketed end of the fitting or valve is slipped over the pipe and solder is run in between them proper heating causes the solder to spread evenly in all directions inside the joint now continuing with the language of piping let's learn the special meaning of some more important words is this all that elbow means to you is TE merely a letter of the alphabet or something your wife drinks does a cross mean a symbol of spiritual Faith or the mark a free man makes in voting or something more well all of these words and some others have their special meanings in pipe fitting an elbow is a fitting that makes a 90° turn in a pipeline for special purposes elbows are also made in 60° 45° and 22 1/ 12° patterns when you need a t in piping it's a fitting shaped like a letter T and it's used to take a right angle line off a run of pipe a cross is like a plus sign it's used where interconnecting pipes intersect then there there is the bushing which is used to reduce the size of a fitting it's helpful in emergencies where you can't get a regular reducing fitting a plug is used for blanking off a line and is often a very important safety precaution and a street L is like a regular L except that it has a male thread on one end you won't have any trouble remembering what a coupling is it connects two lengths of pipe a union does the same thing with the advantage of providing entry into a line unions are important as they permit easy assembly and dismantling of piping Union fittings serve a similar purpose and save nipples as well the flange Union is used in the same way mostly for low pressure work it usually requires a gasket to make a tight joint nipples are of three types the close nipple used where the distance between the connected Parts is very small as threads throughout it entire length a short nipple has a small shoulder between the threads and a long nipple is anything up to 12 in in any size of pipe anything longer is called cut pipe pipe fittings are made of many different materials and until you're familiar with them it may not be easy to tell them apart cast iron and malleable iron fitt look very much alike but the wider band are around the cast iron makes it easy to distinguish from malleable iron although both types are recommended for the same Services many maintenance men have a preference for one or the other some like cast iron because it can easily be broken by a hammer blow when it's necessary to tear down a line others prefer malleable iron because it's tougher and can withstand shark and vibration strains better you can identify Forge Steel by the mark FS or the words Forge Steel on the piece and cast steel fittings at least when they're new usually have a coating of light gray or aluminum paint now what about the different types of valves the two commonest kinds are gate Valves and Globe valves gate valves get their name from the gate likee disc which moves across the path of flow when wide open they offer very little resistance to flow since the seat openings are approximately the same size as the inside diameter of the pipe gate valves work best on wide open or completely closed Services they should never be used for regulating flow because the high velocity of flow past the disc when the valve is partly closed causes severe erosion or cutting of the faces gate valves are made in two general types solid wedge and double disc as with other items of piping materials the maintenance man's choice is likely to depend on his personal preference generally speaking however the wedge disc type is best for most service requirements Globe valves the other common type get their name from the globular shape of the valve body in passing through a globe valve the direction of flow is changed and of course this means greater resistance to free movement the design of globe valves however makes them ideal for even the severest service the regulation of flow sometimes called throttling another feature is that it's easier to regrind the seat and disc of a globe valve now unlike gate valves which come in any size Globe valves larger than 12 in are seldom used because of the extreme difficulty in opening and closing them and in making them tight globe valve discs are made in a number of different types to meet many different service needs the conventional type is sometimes made so that the seating surfaces are rounded like a ball or beveled like this one the plug type is conically shaped making it unusually good for the severest of services in the composition type the disc is generally of some non-metallic material the wide variety of available compositions makes these valves suitable for many kinds of liquid and gas services it should never be used for throttling however because the composition materials will not stand up in such service there's one very important modification of the globe valve design which deserves more consideration than it gets this is the angle valve in basic design angle valves are the same as Globe valves but the pipe openings are at right angles to each other this makes the angle valve convenient where it turns is made in a line used in that way it saves a nipple and an elbow as well as installation time now the various types of gate and Globe valves serve to turn on flow or shut it off but the traffic cups in pipelines are the check valves soall because they prevent or check the reversal of flow now check valves are made in two basic types swing and lift the swing check is much like the gate valve in design for it permits straightway flow generally speaking this is the type of check to use in the same line with gate valves the lift check is much like a globe valve for the direction of flow through the valve body has changed to prevent back flow the disc simply drops to its seat this type is generally used in the same line with globe valves there are many other types of valves including pop safety valves relief valves pressure regulators stop check valves quick opening gate and Globe valves and cucks each of them meets definite needs however the average maintenance man's contact will be mainly with gate Globe angle and check valves so our discussion centers mainly around these types now valves like other piping materials have certain safety limits expressed in their pressure and temperature ratings crane valves for example have symbols like these that tell the story the marking 125s indicates 125 lb steam pressure and 200 W means 200 lb water oil or gas at Cold working pressures now by the way if there's only one figure on the valve body it indicates steam working pressure unless otherwise designated high temperature reduces the safety Factor and cold working pressures are therefore usually higher than the steam pressure markings now if you're uncertain about the marking on a valve look in the Maker's catalog if you don't have the exact makers catalog use anyone that's handy you see working pressures and temperatures for various types of valves are pretty well standardized maximum working temperatures depend upon the material from which the the valve is made for instance iron should not be used on temperatures above 500° or brass where temperatures exceed 550° certain steel valves working at no more than 100° temperature will handle pressures up to 6,000 lb but with a temperature of 1100 de the same valve is good for pressures only up to 1175 lb if you're you have a proper understanding of the qualities of various kinds of valves and fittings you'll realize the importance of handling them intelligently good handling of valves fittings and pipe requires thorough acquaintance with the tools of your trade let's begin with wrenches the pipe wrench a lot of people call it the sson wrench is the most useful tool you will have it's top- notch in the right place but can do a lot of harm if it's wrongly used used one place not to use your pipe wrench is on a valve body if you understand how it works you will know why with this type of wrench the more you pull the harder you squeeze applied to a valve body its crushing effect May distort the piece and ruin it even when it's used in the right way if your wrench is too large it may damage or even break the material on which you're working and of course if your wrench is too small for the job it won't do a satisfactory job either you'll find the monkey wrench with its smooth square jaws almost as important as the pipe wrench the monkey wrench is the right thing to use on a valve it fits better than a pipe wrench and it can't cause damage by crushing the strap wrench is useful when you're working with plated or highly polished pipes and fittings or in close quarters it isn't suitable for heavy work pipe tongues are used like wrenches and although they're made for pipe from 1/8 in diameter and up they're mostly used for a 4 in and larger pipe because of the greater leverage they provide you can't cut and thread pipe without using a vise the pipe Vise is used only for pipe but The Machinist Vice especially if it's of the combination type can be used for both pipe and other purposes useful as it is the Vie can be misused if you lean on the handle too much you can damage the valve body just as you can with a pipe wrench remember to use soft jaws of copper or lead before clapping a valve in a vise so as to prevent damaging the ends in assembling a valve and nipple put the nipple not the valve in the vice use your monkey wrench on the end of the valve nearish the nipple to avoid twisting the valve body that is no so far in fact we've left out one of the most important factors proper cleaning you've all seen p pipe stored where dust will get into it or maybe mud or sand and of course other things can happen to it too what we call foreign matter which means almost anything that we don't like may get into the pipe well what do you do about it you can blow out or swab out this dirt or foreign matter such stuff invariably collects in a valve and may put it out of commission at the very start even if nothing gets inside the threads May pick up a lot of dust dust dirt and grit which can cause trouble when you're making anything as accurate as a threaded joint dirty threads increase friction and make it harder to make a tight connection they may even cause tearing of the metal during screwing up it's better to make sure that both the threads are clean and that a suitable lubricant is used before making up a joint now another thing you can't handle pipe carelessly and expect it to work satisfactorily if you bang it against something hard you'll damage it if there's any chance of that check up on it right away when a male thread is slightly damaged or distorted put a drift in the end to round it out and then run a Dye over the thread to clean it up if a female thread has been damaged be sure that it's clean and then if necessary run through a tap to correct the damage to the threads pipe may need to be reamed to remove bars left from cutting particularly if cut with a rotary cutter this should be done before threading there is the special problem that arises when pipe is cut and threaded on the job these operations may be properly performed but it's always good practice to see that all chips are cleaned off before you try to make a joint screwed connections are the commonest kind of pipe connections they're easy to make in the small sizes and can be properly made by almost anyone pipe threads are tapered and certain standard dimensions have been established for their proper makeup in various sizes this cross-section view shows the relation of the male and female parts in a properly made up joint in order to get a good tight metal toetal joint the first important thing is to see that the threads are clean it's good practice to use a lubricant on the threads to reduce friction when the parts are screwed together put the lubricant only on the male thread so that any excess will be squeezed to the outside of the joint rather than into the pipeline lubricants or pipe dope as they're commonly called should not be expected to compensate for poor workmanship use the proper size wrench too large a wrench will provide too much leverage I don't think that the joint must be tightened until all the exposed threads are concealed if the threads are properly cut and pulled up to the right point the taper of the pipe thread and fitting will ensure a tight metal toetal joint generally flange joints are made up with a gasket between the machine faces of the opposing flanges which are then pulled together with bolts it's important to support the pipe in such a way that the flange faces can be brought into perfect parallel alignment in working on flanged material always clean the faces first cleaning eliminates dirt and grit which might cause damage put half of the bolts through the flanges to hold the gasket when it's dropped into place for this work a ring gasket is used rather than a full face gasket so the bolts do not go through it now put the other bolts in place and when you pull them up don't make the mistake of doing it in rotation around the pipe use the crossover method and tighten opposite pairs of bolts like this 1 2 3 4 5 6 78 this permits uniform loading of the bolts and proper centering which avoids harmful stresses well what we've considered so far might be called the elements of piping every maintenance man as he carries on realizes his need for more knowledge about piping materials especially on how to install and care for valves so let's discuss the subject of how to install a globe valve you'll probably hear a good many arguments on whether such valves should be installed with the pressure above or below the disc R therefore a discussion of these few basic principles may help you determine what course you should follow where Globe valves are to be used on hot surfaces steam or otherwise if the pressure is above the disc the operating mechanism will be kept under temperature continuously this makes for more efficient operation if pressure on hot lines particularly steam lines is installed below the disc the upper part of the valve will tend to cool cooling can cause enough contraction of the stem to lift the disc slightly perhaps enough to cause a little leakage the resulting extremely high velocity of flow may lead to severe erosion of the disc and seat there is one kind of service in which a globe valve should always be installed with the pressure below the disc this is where it's important to have flow continue even if some accident should cause the disc to come off the stem boiler feed service is a typical example but if safety considerations do not make it important for flow to continue the valve will generally give better service and be more easily kept tight if it's installed with the pressure above the disc after valves have been in service for some time they may require either of two servicing operations repacking of the stuffing box or general repairing of the working parts if leakage occurs at the stuffing box shortly after installation it can can be stopped by simply pulling down on the stuffing box nut however if the leak occurs after long service it may be necessary to repack the valve this can often be done without removing the valve from the line use a packing hook to get out all of the old packing manufacturers generally use a ring packing however some plants prefer to use different types of packing for replacement then polish the valve stem with a strip of very fine Emery cloth to remove the little bits of packing and slight scratches that may be present wipe the stem and inside of the stuffing box then put in a few rings of packing use the gland as a tamping tool to Tamp it into the stuffing box continue to add packing until the box is filled if the stuffing box flange is of the two bolt type be careful to pull the bolts up evenly this will avoid the risk of cocking the gland at an angle which would cause binding of the St if a valve continues to leak at the seat remove the Bonnet and clean and examine the disc and body thoroughly in new installations the trouble may be due to dirt or pipe scale if the disc and body rings are very badly damaged repairs may not be practical in some cases the body seat Rings may have to be replaced while the disc can still be saved for a thorough job remove the stem from the Bonnet and examine it for scoring and pitting put the stem in a soft jawed visce for polishing with fine Emy cloth when the stem is polished of course you'll want to repack the stuffing box before reassembling the valve see that the valve Bonnet and other parts are cleaned of dirt scale and corrosion which might damage the valve seats and remember that it doesn't pay to try to salvage most gaskets it's much better to use a new one to remove cuts from the disc set it in a vise with the face leveled then with a piece of Emy cloth wrapped around a flat tool lap the entire bearing surface remove as little metal as possible in getting the required finish then turn the disc over and perform the same operation on the other side remember that this is not a simple job if the body rings are not so badly damaged that they must be replaced remove their cuts and scratches also by lapping use an emay block small enough to permit convenient rubbing of the Ring all around work carefully and watch closely avoid removing too much metal which would cause the disc to seat too low when the seating surfaces disc and body rings are properly lapped apply prussi and blue to the finished faces of the disc and insert it in the body then remove the disc and inspect it if the pan blue is rubbed away excessively from any part of the disc it means that the seating surfaces do not make continuous contact where pressure blue can be seen on the body Rings it indicates the places where further lapping is needed when the high spots have been rubbed down a little wipe the body rings and the disc clean apply a fresh light coat of press and blue and repeat the test it may be necessary to check and correct the job several times before good continuous contact is indicated in reassembling the valve first insert the stem in the Bonnet with the disc on the stem place the assembly in the body raise the disc to prevent contact with the seats and to permit seating the Bonnet properly on the body before tightening the joint before you install the valve be sure to test it for tightness if all these precautions are observed the repaired gate valve will be good for long continued Service Repairs on metal to metal seat globe and angle valves can usually be made without removing them from the line with this feature there's no no excuse for delaying repair of a leaking valve especially since neglect invites serious damage to start this job remove the stem from the Bonnet and place the disc in the Vise using soft Jaws to avoid possible damage unscrew the disc stem ring lift out the stem and insert a slug or coin inside the disc then replace the stem and tighten the ring to lock the disc to the stem now put a little Emy base grind grinding Compound on the disc but remember that too much grinding compound is likely to remove too much metal put the body and the Barnet together and turn the Barnet Ring On Loosely by hand to provide a guide for the stem grasp the hand wheel firmly and isolate it back and forth inspect the work before you think it's completed so as to avoid the risk of grinding more than is necessary if the bearing is not yet smooth replace the bonnet and continue the operation when the grinding is completed wipe the disc thoroughly it should show a continuous smooth bearing on the seating surfaces when tested with bres and blue see that the seat and body are clean of all grinding compound and dirt too then before reassembling the valve be sure to remove the slug from the disc so as to allow it to swivel freely on the stem there's one advantage in using a coin instead of a slug for this purpose it's easier to remember to take it out this simple procedure makes it possible to keep globe and angle valves in good operating condition all the time where composition disc valves are used it's an easy matter to replace the worn disc with a new one be sure to examine the seat in the valve to see that it's not damaged or it may be necessary to remove cuts from it in Plants where many valves of this kind are used it will save time if a number of extra disc holders are kept on hand ready to install then worn discs can be replaced whenever it's convenient now no matter how much you've learned it won't do you any good unless you use it if you learn good shop practices and make them your habits you'll surely make good on the job but you'll find sometimes that all the things you'd like to have to work with aren't available no book and no course of instruction can give you all the piping pointers there are the best answer to some of your problems lies in your own Ingenuity and resourcefulness now if you Le take a copy of this booklet study it and keep it handy you'll find it Mighty useful in your work thank you sir it covers all the points that we've reviewed today and quite a lot of other useful piping pointers that we didn't have time to discuss any of them may be useful perhaps all of them will be in helping you lick the problems that turn up every day on your job that is the friendly wish of crane the world's largest manufacturer of valves the [Music]