Apparatus and method for making custom length pipe nipple

Abstract

An apparatus to make a custom length pipe nipple, and method for use of the apparatus. The apparatus has a male plumbing thread at one end connected to an elongate member, with length or measurement markings along the elongate member. The apparatus is threaded into a plumbing fixture that will be flush mounted against a wall, and then using the markings on the elongate member, a length is determined that corresponds to the flush mounting surface of the plumbing fixture. The apparatus is then threaded into a plumbing fitting, such as a drop ear elbow inside a wall, and a second length is determined that corresponds to a flush mounting surface of the wall. The two lengths are added together to determine the length of a piece of pipe. Tightening and/or caulk allowance may be included, and a piece of copper or iron pipe is then cut to length. For copper pipe, a threaded male copper fitting is solder attached to each end. For iron pipe, the ends are threaded. Depending on whether copper or iron pipe is used, there are different length or measurement markings along the elongate member.

Claims

1. A method for making a custom length soldered copper pipe nipple, the method comprising: screwing a plumbing pipe thread on a first end of an elongate member into a threaded connection of a plumbing fixture, the elongate member having the first end and a second end; using first length measurement markings on the elongate member, determining a first length that corresponds to a length between the threaded connection of the plumbing fixture and a mounting surface of the plumbing fixture, the first length measurement markings increasing from the first end toward the second end, a zero point on the first length markings spaced a first distance from the first end, the first distance the same as a distance between a threaded end of a threaded copper fitting and a shoulder in the threaded copper fitting; screwing the plumbing pipe thread on the first end of the elongate member into a threaded plumbing connection located in a wall; using the first length measurement markings on the elongate member, determining a second length that corresponds to a length between the threaded plumbing connection located in the wall and a mounting surface of the wall; and adding the first length and the second length to determine a cut length.

2. A method according to claim 1, further comprising: including a tightening allowance to determine the cut length.

3. A method according to claim 1, further comprising: adding a caulk allowance to the cut length; and cutting a piece of copper pipe to match the cut length plus caulk allowance.

4. A method according to claim 1, further comprising: cutting a piece of copper pipe to match the cut length; and soldering male threaded couplings to each end of the copper pipe.

5. A method according to claim 4, wherein a maximum diameter of at least one of the thread couplings is substantially the same as the diameter of standard inch plumbing pipe.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The foregoing features and other aspects of the invention are explained in the following description taken in conjunction with the accompanying figures wherein:

(2) FIG. 1 illustrates plumbing connections relevant to embodiments of the instant invention;

(3) FIG. 2 illustrates plumbing fittings relevant to embodiments of the instant invention;

(4) FIG. 3 illustrates embodiments of the instant invention;

(5) FIG. 4 illustrates embodiments of the instant invention;

(6) FIG. 5 illustrates embodiments of the instant invention;

(7) FIG. 6 illustrates embodiments of the instant invention;

(8) FIG. 7 illustrates embodiments of the instant invention; and

(9) FIGS. 8A and 8B illustrate embodiments of the instant invention.

(10) It is understood that the drawings are for illustration only and are not limiting.

DETAILED DESCRIPTION OF THE DRAWINGS

(11) There are a number of instances where a water supply that is routed inside a wall cavity must exit the wall cavity through a hole in a finished wall surface and terminate in a plumbing fixture that is mounted flush or very nearly flush with the finish wall. Examples would include tub fill spouts and supply elbows that connect to a flexible hose for a hand-held shower spray head. If the plumbing fixture is not flush or nearly flush with the finish wall, there will be a gap between the fixture and the finish wall that is unsightly, difficult to fill with caulking, and prone to leaks that will allow water to enter the wall, causing damage.

(12) In many instances, the plumbing fixture connection is a standard plumbing pipe thread, which in the United States is usually inch national pipe thread (NPT). Similarly, it is common to use the same type and size of standard plumbing pipe thread on the fitting that is inside the wall. These fittings in the wall are sometimes call drop ear elbows.

(13) FIG. 1 illustrates this type of common configuration. A wall cavity (101), which is often framed with 24 or 26 dimensional lumber provides a space to route a plumbing supply line. In a bathroom, the finish wall may include cement backer board, or a mortar bed (103), with an over-layer of tile or stone (105) on the outer most surface. Where the water supply line must exit the wall cavity through a hole in the finished wall, it is common to securely attach a drop ear elbow (107) to blocking material (109). This way, the water supply is firmly anchored inside the wall cavity and it will not move easily if it is pulled or pushed. If the water supply is copper pipe, it is common to attach a brass or bronze drop ear elbow to the copper pipe using a solder joint.

(14) In most instances, plumbing inside the wall cavity is completed before the finish wall is installed. This means that after the finish wall is installed, the drop ear elbow is fixed in position and it can not be easily adjusted. In addition, the finish wall thickness depends on the materials used in the finish wall. Where a mortar bed is used under a layer of tile, the thickness of the mortar bed is not standard. The tile or stone thickness will also vary, and there is usually some sort of thinset or adhesive used between the mortar bed and tile. All of this means that the thickness of the finish wall is seldom known until completed. Once completed, the only access to the drop ear elbow is through a small hole (111) in the finish wall. Moving the drop ear elbow in or out is really no longer an option.

(15) On the bath side of the finish wall, there is a plumbing fixture that connects to the water supply. The plumbing fixture might be a bathtub fill spout, or a supply elbow. In FIG. 1, plumbing fixture (113) is illustrated as a supply elbow. It is very important to prevent water from entering the wall cavity, because it is very difficult to know there is a leak until significant water damage has already occurred. For this reason, extra attention is paid to making sure that gaps are filled with caulking or some other water barrier, especially on the side of a shower where the shower head is installed and lots of water runs down the wall. That is also the same side of a shower where a tub fill spout or supply elbow is often installed. Caulking is most effective when it must only fill a small gap, it also looks better when it fills only a small gap.

(16) The connection between the drop ear elbow (107) and the plumbing fixture (113) is usually made with a nipple (115), which is a short piece of plumbing pipe with male threads on each end. Although some pipe nipples for water supply are made of galvanized iron pipe, it is more common to use a brass nipple for this type of connection, particularly where the drop ear elbow is brass or bronze and connects to copper pipe. Brass has an advantage of not corroding or rusting like galvanized iron pipe.

(17) Pipe nipples are generally made and sold in standard lengths. For NPT, there is a close nipple, which is about 1 inches from end to end. Then there is a shoulder nipple that is about 1 inches from end to end. Between 1 inches and 6 inches, pre-manufactured nipples are available in inch increments. Longer than 6 inches, pre-manufactured nipples are available in 1 inch increments.

(18) Because pre-manufactured pipe nipples are only available in certain lengths, if the length needed is not almost the same as the standard length available, there will be either a large gap between the finish wall and the plumbing fixture, or not enough thread engaged to ensure a water-tight connection. To accommodate this problem, plumbers may start with a nipple that is just a bit too short, and wrap the male fitting with extra Teflon tape and/or pipe joint compound to prevent leaks. Or, they may connect multiple shorter couplings with the goal of getting closer to the needed length. Neither solution is ideal.

(19) It is possible to make a custom nipple of almost any length out of brass or iron pipe. However, threading pipe and in particular making a pipe nipple requires specialized tools. Further, making a custom length nipple with a pipe threading machine, especially a short nipple, will almost always require a nipple chuck, which may not be available at the job site.

(20) It is possible to make a nipple of almost any length greater than about 2 inches by soldering standard threaded male copper fittings on each end of a piece of copper pipe. Determining exactly how long that piece of copper pipe should be is a challenge. The instant invention helps to solve that challenge.

(21) As illustrated in FIG. 2, male copper fittings have a threaded portion (201) and a socket (203) that receives a copper pipe. There is a shoulder (205) at the bottom of the socket, and the end of the copper pipe will touch that shoulder when it is fully inserted into the fitting. When the fitting and copper pipe is properly soldered, the resulting joint is water tight, and it has significant mechanical strength.

(22) The dimensions of inch NPT are standardized. So, any inch NPT male copper fitting that is manufactured according to that standard should engage a inch NPT female fitting with substantially the same number of threads. In addition, examination of fittings from multiple manufactures indicates that the socket depth and relationship of the socket to the threads is substantially the same for most inch NPT male copper fittings, regardless of manufacturer. The instant invention takes advantage of these standard dimensions.

(23) As illustrated in FIG. 3, one embodiment of the instant invention has a inch NPT male thread (301) at one end, and a handle (305) at the other end. An elongate member (303) connects the male thread end (301) to handle end (305). There are markings (307) on the elongate member that indicate a length. The length markings begin on the end with the male threads (301), and increase until they stop near the end with the handle (305). The length markings reflect the distance from where a shoulder will occur in a NPT male copper fitting. The 0 point for this embodiment is illustrated.

(24) In one embodiment, the length markings are measured in inches and fractions of an inch. In another embodiment, the length markings are measured in millimeters. In another embodiment, there are multiple instances of the length markings, spaced around a circumference of the elongate member (303). In another embodiment illustrated in FIG. 8A, there are both inch (803) and millimeter (807) markings, spaced around a circumference of the elongate member (303).

(25) In another embodiment, instead of a handle (305) there is a hole through elongate member 303 that allows a screwdriver or other object to be inserted and used as a handle to turn and tighten the elongate member into a plumbing fitting or fixture.

(26) In use, the threaded end (301) is engaged with female threads in a fitting that is inside the wall cavity. That fitting in the wall cavity might be a drop ear elbow. Using handle 305, the device is hand-tightened until the threads have made good contact, but it is not over-tightened such as a typical pipe fitting would be tightened to create a water-tight connection. Then, the length marking on elongate member (303) is determined that best corresponds to a flush surface of the finished wall. We can refer to this as a first length. This is illustrated in FIG. 4.

(27) The threaded end of the device is disengaged from the fitting inside the wall cavity, and it is engaged with female threads in the plumbing fixture that will be connected to the water supply. Once again, using handle 305, the device is hand-tightened until the threads have made good contact. And as before, a length marking is determined that best corresponds to a flush surface of the plumbing fixture. We can refer to this as a second length. See FIG. 5.

(28) An exact length for the copper pipe is determined by adding the first length and second length together. However, this exact length does not include any allowance for tightening, so a tightening allowance may be added to the exact length. Depending on the plumber's preference, the tightening allowance may be something between one and two turns. inch NPT has 14 threads per inch, and 1 or 2 turns of inch NPT is between about 3/32 and 5/32 inches (or between about 1 and 4 mm). Balanced with an increase in length from a tightening allowance is a potential decrease in length from using tape or joint compound to seal the joint. In most applications, these connections are never highly pressurized, so between 0 inches and about inch or 3 mm of tightening allowance may be sufficient.

(29) It may also be desirable to have a small gap of about 1/16 to inch between the plumbing fixture and the finished wall, for a caulk joint. If so, a caulk allowance is also added to the calculated length.

(30) Using the calculated length, a piece of copper pipe is then cut and male copper thread fittings are soldered to each end. The custom length pipe nipple is then installed according to standard practice, using joint compound and/or tape, and after tightening, the plumbing fixture should be the desired distance from the finished wall.

(31) For most plumbing fixtures, a standard male copper thread fitting will work without any problem. However, standard male copper thread fittings have hex flats so the fitting can be turned and tightened with a wrench. (See 601 in FIG. 6). For some plumbing fixtures the additional diameter associated with the hex flats on the fitting will interfere with the fixture. For those plumbing fixtures, it is necessary to use a male copper thread fitting that does not have hex flats, and has an outside diameter no greater than the outside diameter of standard inch NPT pipe (about 0.840 inches). Such a modified male copper thread fitting is illustrated as 603 in FIG. 6.

(32) In the embodiments described above, it has been assumed that copper pipe and copper thread fittings soldered to the copper pipe are used to make the custom length pipe nipple. In these embodiments, the 0 point of the apparatus corresponds to where a shoulder occurs in a threaded male copper fitting. (See apparatus 701 in FIG. 7). It is also possible to use a similar apparatus to determine the length of a custom nipple that is threaded from iron or brass pipe. In this embodiment, as illustrated by apparatus 703 in FIG. 7, the 0 point corresponds to the end of the plumbing pipe thread.

(33) FIG. 8B illustrates an embodiment with a first plumbing pipe thread (805) on a first end and a second plumbing pipe thread (801) on a second end, with length markings (807) that begin near the first end and indicate a length measured from an end of the first plumbing pipe thread (805), and length markings (803) that begin near the second end and indicate a length measured from the point where a copper pipe shoulder would occur in a threaded copper fitting.

(34) Although illustrative embodiments have been described herein in detail, it should be noted and will be appreciated by those skilled in the art that numerous variations may be made within the scope of this invention without departing from the principle of this invention and without sacrificing its chief advantages. For example features that appear in one embodiment of a particular figure are also applicable to embodiments that are illustrated in other figures.

(35) Unless otherwise specifically stated, the terms and expressions have been used herein as terms of description and not terms of limitation. There is no intention to use the terms or expressions to exclude any equivalents of features shown and described or portions thereof and this invention should be defined in accordance with the claims that follow.