WO1997033118A1

WO1997033118A1 - Elbow tee fitting

Info

Publication number: WO1997033118A1
Application number: PCT/US1997/003454
Authority: WO
Inventors: John F. Cates, Jr.
Original assignee: WFI International Inc
Current assignee: WFI International Inc
Priority date: 1996-03-08
Filing date: 1997-03-06
Publication date: 1997-09-12
Anticipated expiration: 1998-09-08
Also published as: AU1987997A

Abstract

A pipe fitting (F) adapted to be mounted in a piping system and to receive a thermowell and thermocouple. The pipe fitting (F) comprising a unitary member having an upstream bore (16) and a downstream bore (18). The upstream bore (16) is in fluid communication with the downstream bore (18) and oriented approximately 90 degrees relative to the downstream bore (18). The unitary member (F) has a port (20) in coaxial alignment with the upstream bore (16) and includes an internal shoulder portion (24) having a reduced diameter smaller than the diameter of the upstream bore (16).

Description

ELBOW TEE FITTING The present invention relates generally to pipe fittings, and more particularly to a pipe fitting adapted to receive a thermowell and thermocouple assembly.

Typically, a pipe fitting is a one-piece metal coupling having a bore therethrough and having some type of end portions adapted to be welded onto or connected to other piping or pipe fittings. Pipe fittings are manufactured in various configurations which are commonly required in piping systems. For example, bends in piping systems are commonly accomplished with elbow fittings. Elbow fittings are available in a variety of angles, with the most common angles being 45° and 90°. Wyes and tees are also common types of pipe fittings used, among other things, to have branched piping routes.

It is fairly common in piping systems to measure the temperature of a process fluid within the piping system. One common way of measuring the temperature of the process fluid is by inserting a thermocouple into the piping system. Typically, the thermocouple includes an elongate, slender rod member which is inserted in the piping system. The rod member of the thermocouple is preferably positioned longitudinally within the pipe member and along the central axis of the pipe member. This orientation and location is preferable to obtain accurate temperature readings.

In the past, in order to orient the thermocouple on the longitudinal axis of the pipe member, the thermocouple was generally inserted into the piping system at the location of a 90° bend, typically formed with a 90° elbow fitting. In order to accommodate and receive the thermocouple and thermoweU, a hole would first be cut in the elbow fitting and a short pipe section adapted to receive the thermowell and thermocouple would be welded to the elbow fitting.

Oftentimes, thermocouples are required in critical industries such as the chemical industry where it is necessary that each weld be x-rayed. The labor cost and time involved in preparing and machining a weld, x-raying the weld, and other weld inspection makes each weld important. Further, each additional weld is a point of potential weakness and thus the elimination of welds wherever possible is desirable.

It is desirable to have a one-piece construction elbow fitting adapted to receive and accurately align a thermowell and thermocouple assembly. It is also desirable to have an elbow fitting adapted to receive a thermowell and thermocouple assembly which minimizes stress points, provides a clean seamless bore, reduces construction costs, and eliminates difficult welds and weld inspections. It is also desirable that the elbow fitting provide for compact reception of the thermowell and thermocouple assembly.

The elbow tee fitting of the present invention is a one-piece construction elbow fitting adapted to receive and accurately align a thermowell and thermocouple assembly.

The elbow tee fitting minimizes stress points, provides a clean seamless bore, reduces construction costs, and eliminates difficult welds and weld inspections. The elbow tee fitting also provides compact reception of the thermowell and thermocouple assembly.

The elbow tee fitting includes an upstream opening and a downstream opening oriented, preferably 90°, relative to one another. The elbow tee fitting further includes an upstream bore in fluid communication with a downstream bore. Typically, the upstream and downstream bores have a common inside diameter.

The elbow tee fitting includes a port in coaxial alignment with and in fluid communication with the upstream bore. The port includes an outer receiving portion which terminates at an internal shoulder portion having a reduced diameter. The elbow tee fitting has a generally cylindrical external portion extending along the longitudinal axis of the upstream bore and the port. Preferably, a short downstream projection extends from the generally cylindrical external portion. Preferably, the joinder of the downstream projection and the cylindrical external portion includes a radiused wall and an increased wall thickness to minimize stress concentration at this point. Preferably, the elbow tee fitting is forged from a single piece of material to eliminate stress points and provide clean seamless bores.

The port of the elbow tee fitting is adapted to receive a flange portion and a connecting portion of a thermowell. The internal shoulder portion is adapted to slidably receive the flange portion of the thermowell and align a tube portion of the thermowell within the upstream bore. The outer receiving portion of the elbow tee fitting is adapted to receive the connecting portion of the thermowell. The connection of the thermowell with the elbow tee fitting provides a fluid tight seal.

In order to more fully understand the drawings referred to in the detailed description of the present invention, a brief description of each drawing is presented, in which: Fig. 1 is a perspective view of an elbow tee fitting according to a first embodiment of the present invention;

Fig. 2 is a cross-sectional elevational view of the elbow tee fitting of Fig. 1 showmg a thermowell and thermocouple installed therein; and Fig. 3 is a cross-sectional elevational view of an elbow tee fitting according to a second embodiment of the present invention.

Referring to the drawings, the letter F generally designates the elbow tee fitting of the present invention. A first embodiment 10 of the elbow tee fitting F is shown in Figs.

1 and 2 and a second embodiment 100 is shown in Fig. 3. The differences between the first and second embodiments 10 and 100, respectively, will be described below. It is to be understood that identical features of the first and second embodiments 10 and 100, respectively, will be referred to by the same reference numeral. Where the features are different in the second embodiment 100, a three digit numeral will be used.

Referring to Figs. 1-3, the elbow tee fitting F includes an upstream opening 12 and a downstream opening 14 oriented, preferably 90°, relative to one another. As shown in

Fig. 1, the openings 12 and 14 are round. The elbow tee fitting F includes an upstream bore 16 in fluid communication with a downstream bore 18 as shown in Figs. 2 and 3.

The openings 12 and 14 and the bores 16 and 18 have a common inside diameter D as shown in Figs. 2 and 3. The elbow tee fitting F includes a port 20 in coaxial alignment with and in fluid communication with the upstream bore 16. The port 20 includes an outer receiving portion 22 which terminates at an internal shoulder portion 24 having a reduced diameter.

In the first embodiment 10 as shown in Figs. 1 and 2, the outer receiving portion 22 is a smooth wall 23. In the second embodiment 100 as shown in Fig. 3, the outer receiving portion 22 includes threads 123 for reasons which will be explained below.

As shown in Fig. 1, the elbow tee fitting F includes a generally cylindrical external portion 26 extending along the longitudinal axis of the upstream bore 16 and the port 20.

Preferably, a short downstream projection 28 extends from the generally cylindrical external portion 26. Preferably, the joinder of the downstream projection 28 and the cylindrical external portion 26 includes a radiused wall and an increased wall thickness as shown in Figs. 2 and 3 to minimize stress concentration at this point. Preferably, the elbow tee fitting F is forged from a single piece of material to eliminate stress points and provide clean seamless bores 16, 18 and 20.

Referring to Fig. 2, the elbow tee fitting F is adapted to receive a thermowell 40 and a thermocouple 60. Thermocouples 60 and thermowells 40 are available in many different varieties from various manufacturers. One such manufacturer of thermocouples 60 and thermowells 40 is Thermo Sensors Corporation, Garland, Texas.

Referring to Fig. 2, the thermocouple 60 includes an elongate, slender rod member 62 connected to a mounting portion 64. Typically, the mounting portion 64 has an exterior threaded portion as shown in Fig. 2. Still referring to Fig. 2, the thermowell 40 includes a tube portion 42, a flange portion 44 and a connecting portion 46. The thermowell 40 also includes a longitudinal recess 48 and a receiving socket 50. Preferably, the longitudinal recess 48 and the tube portion 42 are concentric with the flange portion 44 and connecting portion 46.

The thermowell 40 is adapted to receive the thermocouple 60. As shown in Fig. 2, the slender rod member 62 extends into the thermowell longitudinal recess 48 and the threaded mounting portion 64 is received in the receiving socket 50. The tube portion 42 protects the slender rod member 62 from being damaged by the flowing process fluid as will be explained below.

The port 20 ofthe elbow tee fitting F is adapted to receive the flange portion 44 and me connecting portion 46 ofthe thermowell 40. Referring to Fig. 2, the internal shoulder portion 24 of the elbow tee fitting F is adapted to slidably receive the flange portion 44 ofthe thermowell 40 and align the tube portion 42 within the upstream bore 16. The outer receiving portion 22 ofthe elbow tee fitting F is adapted to receive the connecting portion 46 ofthe thermowell 40. In the first embodiment 10 as shown in Fig. 2, the thermowell 40 is secured to the elbow tee fitting F by a weld 52. The connection of the thermowell 40 with the elbow tee fitting F providing a fluid tight seal. In the second embodiment 100 as shown in Fig. 3, the thermowell 40 would have a threaded portion (not shown) adapted to thread into the threaded portion 123 of the outer receiving portion 22.

It is to be understood that the elbow tee fitting F is installed such that the upstream opening 12 is connected to piping (not shown) in the direction from which the process fluid flows (the upstream side) and the downstream opening 14 is connected to piping (not shown) in the direction to which the process fluid flows (the downstream side). The proper installation is required because it is desirable that the thermocouple be pointed in the upstream direction.

It is to be understood that the tube portion 42 and the slender rod member 62 extend along the longitudinal axis ofthe upstream bore 16 to a point intersecting the longitudinal axis of the downstream bore 18. Preferably, the tube portion 42 extends beyond the intersection with the longitudinal axis of the downstream bore 18.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention.

Claims

1. A pipe fitting adapted to be mounted in a piping system and to receive a thermowell and a thermocouple, the pipe fitting comprising a unitary member having an upstream bore and a downstream bore, said upstream bore in fluid communication with said downstream bore and oriented approximately 90° relative to said downstream bore, said unitary member having a port in coaxial alignment with said upstream bore, said port including an internal shoulder portion having a reduced diameter smaller than the diameter of said upstream bore.

2. The pipe fitting of claim 1, wherein the thermowell includes a flange portion and said internal shoulder portion is adapted to slidably receive the thermowell flange portion.

3. The pipe fitting of claim 2, wherein the thermowell includes a connecting portion and said port includes a receiving portion adapted to receive the thermowell connecting portion.

4. The pipe fitting of claim 1, wherein said unitary member is a forging.

5. A pipe fitting assembly for measuring the temperature of a process fluid within a piping system, the pipe fitting comprising: a unitary member having an upstream bore and a downstream bore, said upstream bore in fluid communication with said downstream bore and oriented approximately 90° relative to said downstream bore, said unitary member having a port in coaxial alignment with said upstream bore, said port including an internal shoulder portion having a reduced diameter smaller than the diameter of said upstream bore; and a thermowell having a flange portion and said internal shoulder portion is adapted to slidably receive and align said thermowell flange portion.

6. The pipe fitting of claim 5, wherein said thermowell includes a connecting portion and said port includes a receiving portion adapted to receive said thermowell connecting portion.

7. The pipe fitting of claim 5, wherein said unitary member is a forging.

8. The pipe fitting of claim 5, further comprising a thermocouple adapted to be received in said thermowell.

9. A pipe fitting adapted to be mounted in a piping system, the pipe fitting comprising a unitary member having an upstream bore and a downstream bore, said upstream bore in fluid communication with said downstream bore and oriented approximately 90° relative to said downstream bore, said unitary member having a port in coaxial alignment with said upstream bore, said port including an internal shoulder portion having a reduced diameter smaller than the diameter of said upstream bore.

10. The pipe fitting of claim 9, wherein said unitary member is a forging.

11. The pipe fitting of claim 9, wherein said upstream bore has a first diameter and said downstream bore has a second diameter, said first diameter and said second diameter being the same.

12. The pipe fitting of claim 9, wherein said port is in fluid communication with said downstream bore.

13. The pipe fitting of claim 1 , wherein said port is in fluid communication with said downstream bore.

14. The pipe fitting of claim 5, wherein said port is in fluid communication with said downstream bore.