Pipe dope

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Pipe dope is any thread lubricant, thread sealing compound, or anaerobic chemical sealant that is used to make a pipe thread joint leakproof and pressure tight. [1] It is also referred to as "thread compound" or "pipe thread sealant." [2] Although common pipe threads are tapered and therefore will achieve an interference fit during proper assembly, machining and finishing variances usually result in a fit that does not result in 100 percent contact between the mating components. The application of pipe dope prior to assembly will fill the minute voids between the threads, thus making the joint pressure tight. Pipe dope also acts as a lubricant and helps prevent seizing of the mating parts, which can later cause difficulty during disassembly.

Contents

Composition

A material safety data sheet reports that the "Permatex" 51D pipe joint compound contains kaolin clay, vegetable oil, rosin, ethanol, etc. [3] The ingredients are designed to:

  1. fill minute spaces between mating pipe fittings (kaolin), and
  2. serve as a lubricant as the fittings are forced together (vegetable oil).

Various types of pipe dope formulation exist, the appropriate type being determined by the application, e.g., pneumatic, hydraulic, caustic, etc., [4] as well as the expected pressure. Improper selection of the type of pipe dope may result in leakage despite the best assembly practices.

As recently as the 1950s, toxic lead oxide mixed with spar varnish was used as a dope for drinking water pipes. Litharge (a form of lead oxide) mixed with glycerine was also used in some applications. [5] Litharge was also the recommended pipe dope for fuel piping. [6]

Pipe dopes used in oil drilling frequently include powdered graphite, lead and zinc, and sometimes copper suspended in grease. In the past, nickel, talc, silica, calcium carbonate and clay have been included. Heavy metals make up to 25% of the volume of the dope. Silicone is included to improve application to wet or cold surfaces. [7] [8]

Plastic pipes

Petroleum-based pipe dope is not intended for use on threaded PVC, CPVC or ABS pipe and fittings since it will deteriorate the plastic. Builders in the US are expected to use thread compounds that meet ASTM F2331 - Standard Test Method for Determining Chemical Compatibility of Thread Sealants with Thermoplastic Threaded Pipe and Fittings Materials or thread seal tape on PVC, CPVC and ABS threads.[ citation needed ]

Related Research Articles

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<span class="mw-page-title-main">Plumbing</span> Systems for conveying fluids

Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal, and potable water delivery are among the most common uses for plumbing, but it is not limited to these applications. The word derives from the Latin for lead, plumbum, as the first effective pipes used in the Roman era were lead pipes.

A flange is a protruded ridge, lip or rim, either external or internal, that serves to increase strength ; for easy attachment/transfer of contact force with another object ; or for stabilizing and guiding the movements of a machine or its parts. Flanges are often attached using bolts in the pattern of a bolt circle.

<span class="mw-page-title-main">Thermoplastic</span> Plastic that softens with heat and hardens on cooling

A thermoplastic, or thermosoftening plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling.

<span class="mw-page-title-main">Drill string</span> Drill pipe that transmits drilling fluid

A drill string on a drilling rig is a column, or string, of drill pipe that transmits drilling fluid and torque to the drill bit. The term is loosely applied to the assembled collection of the smuggler pool, drill collars, tools and drill bit. The drill string is hollow so that drilling fluid can be pumped down through it and circulated back up the annulus.

<span class="mw-page-title-main">National pipe thread</span> U.S. national technical standards for threads on pipes and pipe fittings

American National Standard Pipe Thread standards, often called national pipe thread standards for short, are United States national technical standards for screw threads used on threaded pipes and pipe fittings. They include both tapered and straight thread series for various purposes, including rigidity, pressure-tight sealing, or both. The types are named with a full name and an abbreviation, such as NPT, NPS, NPTF, or NPSC.

<span class="mw-page-title-main">Compression fitting</span>

A compression fitting is a fitting used in plumbing and electrical conduit systems to join two tubes or thin-walled pipes together. In instances where two pipes made of dissimilar materials are to be joined, the fittings will be made of one or more compatible materials appropriate for the connection. Compression fittings for attaching tubing (piping) commonly have ferrules in them, and are sometimes referred to as flareless fittings. There are also flare fittings that do not require ferrules/olives.

Grease is a solid or semisolid lubricant formed as a dispersion of thickening agents in a liquid lubricant. Grease generally consists of a soap emulsified with mineral or vegetable oil.

<span class="mw-page-title-main">Static mixer</span>

A static mixer is a precision engineered device for the continuous mixing of fluid materials, without moving components. Normally the fluids to be mixed are liquid, but static mixers can also be used to mix gas streams, disperse gas into liquid or blend immiscible liquids. The energy needed for mixing comes from a loss in pressure as fluids flow through the static mixer. One design of static mixer is the plate-type mixer and another common device type consists of mixer elements contained in a cylindrical (tube) or squared housing. Mixer size can vary from about 6 mm to 6 meters diameter. Typical construction materials for static mixer components include stainless steel, polypropylene, Teflon, PVDF, PVC, CPVC and polyacetal. The latest designs involve static mixing elements made of glass-lined steel.

<span class="mw-page-title-main">Pipe (fluid conveyance)</span> Tubular section or hollow cylinder

A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipe is far stiffer per unit weight than solid members.

<span class="mw-page-title-main">Threaded pipe</span>

A threaded pipe is a pipe with screw-threaded ends for assembly.

<span class="mw-page-title-main">Thread seal tape</span> Tape commonly used in plumbing

Thread seal tape is a polytetrafluoroethylene (PTFE) film tape commonly used in plumbing for sealing pipe threads. The tape is sold cut to specific widths and wound on a spool, making it easy to wind around pipe threads. Thread seal tape lubricates allowing for a deeper seating of the threads, and it helps prevent the threads from seizing when being unscrewed. The tape also works as a deformable filler and thread lubricant, helping to seal the joint without hardening or making it more difficult to tighten, and instead making it easier to tighten. It also protects the threads of both pieces from direct contact with each other and physical wear and helps seal and prevent leaks from the connection.

<span class="mw-page-title-main">Piping and plumbing fitting</span> Connecting pieces in pipe systems

A fitting or adapter is used in pipe systems to connect straight sections of pipe or tube, adapt to different sizes or shapes, and for other purposes such as regulating fluid flow. These fittings are used in plumbing to manipulate the conveyance of water, gas, or liquid waste in domestic or commercial environments, within a system of pipes or tubes.

<span class="mw-page-title-main">Pipefitter</span> Tradesman who works with mechanical pipes

A pipefitter or steamfitter is a tradesman who installs, assembles, fabricates, maintains, and repairs mechanical piping systems. Pipefitters usually begin as helpers or apprentices. Journeyman pipefitters deal with industrial/commercial/marine piping and heating/cooling systems. Typical industrial process pipe is under high pressure, which requires metals such as carbon steel, stainless steel, and many different alloy metals fused together through precise cutting, threading, grooving, bending, and welding. A plumber concentrates on lower pressure piping systems for sewage and potable tap water in the industrial, commercial, institutional, or residential atmosphere. Utility piping typically consists of copper, PVC, CPVC, polyethylene, and galvanized pipe, which is typically glued, soldered, or threaded. Other types of piping systems include steam, ventilation, hydraulics, chemicals, fuel, and oil.

<span class="mw-page-title-main">Grease fitting</span> Metal fitting used in mechanical systems to feed lubricants

A grease fitting, grease nipple, Zerk fitting, grease zerk, or Alemite fitting is a metal fitting used in mechanical systems to feed lubricants, usually lubricating grease, into a bearing under moderate to high pressure using a grease gun.

<span class="mw-page-title-main">Lincoln Industrial</span>

Lincoln Industrial Corporation (Lincoln) is a manufacturer of automated lubrication systems, manual lubrication equipment and industrial pumping systems, and subsidiary of Svenska Kullagerfabriken AB (SKF). Founded in 1910, the company has been responsible for many of the inventions that established modern lubrication practices in automotive maintenance and industry.

Dry lubricants or solid lubricants are materials that, despite being in the solid phase, are able to reduce friction between two surfaces sliding against each other without the need for a liquid oil medium.

<span class="mw-page-title-main">Plastic pipework</span> Tubular section or hollow cylinder made of plastic

Plastic pipe is a tubular section, or hollow cylinder, made of plastic. It is usually, but not necessarily, of circular cross-section, used mainly to convey substances which can flow—liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipes are far stiffer per unit weight than solid members.

Weld-On is a division of IPS Corporation, a manufacturer of solvent cements, primers, and cleaners for PVC, CPVC, and ABS plastic piping systems. Weld-On products are commonly used for joining plastic pipes and fittings. Weld-On also manufactures specialty products from repair adhesives for leaking pipes, pipe thread sealants / joint compounds, to test plugs for pipeline pressure testing. Their products are most commonly utilized in the irrigation, industrial, pool & spa, electrical conduit, and plumbing industries.

<span class="mw-page-title-main">Metal hose</span>

A metal hose is a flexible metal line element. There are two basic types of metal hose that differ in their design and application: stripwound hoses and corrugated hoses.

References

  1. "Plant Engineering | Guidelines For Choosing A Pipe Thread Sealant". Plant Engineering. 1998-03-01. Retrieved 2021-05-20.
  2. "How to Use Pipe Thread Sealant: An Essential Guide". QRFS - Thoughts on Fire Blog. 15 September 2020. Retrieved 2021-05-20.
  3. "Safety Data Sheet" (PDF).
  4. "Thread Sealants". www.henkel-adhesives.com. Retrieved 2021-05-20.
  5. Pipe Fitter 3&2 Navy Training Courses NAVPERS 10592-A, Bureau of Naval Personnel, U.S. Govt. Printing Office, 1953; page 277.
  6. M. S. Howard, Erecting an Oil Engine, Power Plant Engineering, Vol. XXVI, No. 18 (Sept. 15, 1922); pages 902-904.
  7. Darrell P. Salisbury and Robert L. Sloan, Process for Cleaning Pipe Dope and Other Solids from Well Systems, U.S. Patent 5,676,763 , granted Oct. 14, 1997.
  8. John D. Watts and Beverly W. Ramos, Wedgethread Pipe Connection, U.S. Patent 6,682,101 , granted Jan. 27, 2004; see claim 24.