US2059409A - Sealing composition - Google Patents

Description

Patented Nov. 3, 1936 SEALING COIVHOSITION Fred Stevens, Birmingham, Ala., assignor' to American Cast Iron Pipe Company, Birmingham, Ala., a corporation of Georgia No Drawing. Application June 1, 1935, Serial No. 24,583

6 Claims.

ing used to effectively seal a threaded or other joint in cast iron, steel or other metals. The essential function of every threading compound is to reduce friction and obtain a metal to metal contact in the joint. It has been demonstrated that my present new and improved compound enables this to be accomplished much better than 'is possible with other compositions heretofore known and used for the same purpose. The na- .ture, function, utility, alternative modifications,

practical application, methods of preparation, and special qualities of the compound, as well as "various satisfactory formulae for compounding the ingredients of this material, will be readily understood from the following description, which is sufliciently exact to enable a skillful user to practice the same; at the end of which description the invention is carefully summed up and covered in several clauses of claim, and the breadth of the invention is not to be limited in any way except by the claims.

My improved composition consists of three ingredients, namely, paraiflne, White lead and linseed oil. These are mingled or combined together in specified proportions and by suitable methods of admixture as well as in different forms or conditions, but the paraffine is the basic element of the compound, and in order to gain the best results the paraffine is generally used in a volume in excess of that of the other two elements, and sometimes it is very greatly in excess; but in every variation in the proportions of the ingredients by volume the paraiflne is in suspension in the mixture in the form of flakes, particles or globules for it combines readily with the oil and is distributed rapidly throughout the mixture. Wherefore the composition is always normally plastic or soft, and never brittle or hard, or of great density. This result is insured in the .largest degree when the paraffine predominates,

but much latitude may be allowed in the proportioning of the parafline to the white lead and the linseed oil without sacrificing the value of the invention. The white lead gives pliability and flexibility and the paraffine unites intimately with the linseed oil so that the mass is kept plastic or fluent, and is easily applied, and is never indurated. I do not confine myself to the use of all the specific ingredients, but contemplate the use of their equivalents without restricting myself to unessential details. Possibly the white lead may be omitted or at least substituted with a natural filler.

I will proceed now to describe certain leading ways or examples among many that may be set forth in which my improved thread compound may be prepared and used, from which it will be seen that while the white lead and the linseed oil are important, yet they may at times be substituted with equivalent substances having similar 10 properties, while the prafline usually in a disproportionate volume is of paramount value.

In one example of making up the sealing material, equal parts of commercial white lead, linseed oil and parafiine are used. This mixture is heated slightly above the melting point of parafflne, and then very thoroughly commingled. While the mixture is hot it is a relatively thin liquid and can then be applied tothe threads of a pipe, or to any other part, with a brush after which it almost immediately solidifies. The compound so formed produces satisfactory results, but somewhat less in effectiveness than when the parafline is in excess of the other elements. Obviously, the application on the threads of a pipe takes place before screwing the pipes together to make a pipe joint.

In a second suggestive example confirmed by experience, one part of white lead is used to one part of linseed oil, and twenty-five parts of melted parafline. This mixture may be beaten up with an ordinary power beater and when it cools it will be in the form of a fluffy paste. It is applied in the paste form after it has cooled, to the pipe threads or other metallic surfaces.

A third example or way in which the material isdeveloped for use is to take one part of white lead, one part of linseed oil, two parts of powdered parafiine or other wax, all by volume, and mix them together with an ordinary power beater and without theapplication of any heat. The powdered paraffine is obtained in any simple or convenient Way, as, for example, by taking the ordinary cake parafline and grating it through a twenty-one more or less mesh screen to reduce it to a flakelike form. When admixed with the other ingredients the flaked or powdered parafflne, or particles of the same, will be in suspension. This mixture is applied cold to the threads 5 or to any other metallic surfaces. Obviously, all these mixtures could be prepared equally as well through the use of the pugmill or any other similar mechanical device. My mixture can be made, and has been so made, in small quantities in the form of a paste by the use of a mortar and pestle. Manufacturing in large quantities would be more satisfactorily carried on with any of the known types of power operated mixers, preferably of the type having rotary stirring blades.

A preferred formula, which produces most excellent results, consists of four hundred parts of paraffine by volume, fifteen parts of commercial White lead by volume, and fifteen parts of linseed oil by volume. The paraffine is first grated through a twenty-four mesh screen (more or less) to the form of flakes or particles or a powder. This powder, or the flakes, is placed in a container to which is added the White lead, which is in the form of a paste which contains a certain amount of linseed oil. The linseed oil in the proportion above specified is then added gradually while the mixture is being stirred and beaten up with an ordinary rotary beater, or other device. This mixture is made without the application of heat and is normally plastic. It remains in a pastelike condition with the paraffine powder or flakes or particles in suspension, and is applied cold, and can be easily transported, and is therefore admirably adapted to the commercial market. The paste form of the white lead, which means that it has been previously mixed with the linseed oil, is preferred to the form of pure white lead, which is a dry powder. In this preferred form of the compound the parafiine, as stated, is greatly in excess of the other ingredients, and is in suspension in the form of flakes or particles or globules.

Other drying or vegetable oils of the nature of linseed oil may be substituted for it with success. The use of white lead is not absolutely indispensable. Sometimes it may be wholly omitted, but usually there will be a substitution of some other similar substance having like properties, particularly pliability and flexibility, so that said substituted material can be made to serve as a neutral filler. But the parafiine is preeminently important in my material, and is indispensable in some substantial quantity, if not in excess, and is not to be substituted for any other substances unless they be similarly waxlike and with substantially the same physical properties.

White lead alone, which has heretofore often been used for a purpose similar to that of my improved thread compound, does not possess the lubricating qualities of my improved parafiine compound. Neither do other commercial compounds with which I am familiar.

Take the following practical example of a comparative use. In screwing up joints, both male and female, which are of castiron, coated with the ordinary well known compounds, it is quite common to break off the male end of the pipe because the joint is overstressed before the parts are screwed fully home. Through the use of my improved paraffine compound it has been found possible to screw the threaded end farther in, sometimes obtaining as much as one or two threads additional entrance before cracking the tapped hub. Further, for instance, in making up a two inch castiron pipe threaded joint in which one end of the pipe has a tapped hub, and the other end has a threaded spigot, when using ordinary commercial compounds it has been found that a joint may appear to be tight when being threaded up with a twenty-four inch wrench, but which in fact is not tight. By the use of a fortyeight inch wrench handle it is usually possible to give the pipe perhaps another one-quarter or onehalf turn. handle will almost invariably break the spigot end of the pipe off near the threads. When my improved parafiine compound is used, a twentyfour inch wrench is suiiicient to keep threading the spigot end into the tapped socket to the point 10 where the socket is split, due to the tapered threads, and this is usually several turns more, or, in other words, several more threads engagement than is possible with white lead alone, and

other commercial types of threading compounds 15 that are used. Of course my new compound insures a tighter joint against leakage and indicates a more perfect metal to metal contact. It will be understood that the joints may be easily unscrewed at any time, and the metal surface will be found clean and bright; hence joints can be taken down after long use with great ease and without damage to the engaging surfaces. My compound is applicable to sealed joints of all kinds in a great variety of pipe lines carrying steam, all kinds of gases and oils and other substances, and also in making tight joints for manhole and handhole covers in tanks or stills or boilers operating at a high temperature, and in a great diversity of different kinds of threaded or 30 other joints used in connection with a very large number of different kinds of machinery operating in various industrial lines.

I have heretofore stated that the use of white lead is not absolutely indispensable, and some- 35 times it may be wholly omitted, if a proper substitute is made for a neutral filler. In my experience I have demonstrated this and have secured satisfactory results by the use of such substitutes as powdered asbestos and also fine clay dust, provided they are mixed with the other ingredients essential to form a successful mixture.

What I claim is: 1. A sealing composition of the class described,

consisting of White lead, linseed oil, and parafline" particles in suspension.

2. A sealing composition of the character described, consisting of a mixture of linseed oil, a plastic filler, and parafiine, the latter in excess of the oil and filler, the mixture being normally' plastic.

3. A sealing composition of the class described, consisting of commercial white lead, linseed oil, these two ingredients being equal in volume, and.

paraffine in a suflicient volume to form the basis' 55 6. A sealing composition of the class describedf consisting of white lead in a commercial pastelike form, fifteen parts, linseed oil, fifteen parts, and paraffine, four hundred parts, the mixture being normally pastelike.

FRED STEVENS.

Still further turning of the wrenchv 5