Printed

Tubing And Hose Systems

---

Lesson 1 TUBING FUNDAMENTALS
Tubing may be used as an alternative to pipe & in some applications, is better than pipe. Since tubing is not threaded like pipe, tubing material is generally thinner. Lighter, & easier to handle. It can be bent around obstacles & therefore needs fewer connections. The flexibility of tubing also offers advantages over pipe in certain installations.
Copper is perhaps the most common tubing material. Copper tubing comes in different wall thicknesses & tempers & may be used for a variety of applications, including water & air lines. Other tubing materials include stainless steel for high-pressure installations & various plastics for food preparation applications.
Some tubing fittings can be soldered, welded, or brazed. Others compress or swage the tubing. For flared fittings, the end of the tubing must be flared or flanged before the nut is tightened. Since tubing fittings make union connections, installation, maintenance, and repair are relatively simple. Tubing cutters & saws leave burrs & rough edges which you must ream or file before making a connection.
When measuring tubing, it is important that your calculations are accurate. Always use the centerline of the tubing as a reference for measurement. The angle of a bend, the direction of the bend, the radius of the bend, the OD of the tubing you must have a thorough understanding of all of these in order to use a bending tool correctly.
Lesson 2 INSTALLING TUBING
The selection of the material to e used for a tubing application is based on the substance to be carried and the requirements of the system. These service conditions determine the wall thickness and strength of the tubing based on flow rate, pressure, and temperature. You must always allow for a safety factor when you make these computations.
In addition to a variety of fittings, tubing connections may be soldered or brazed. Most soldering is done with copper tubing. Remember to wear safety glasses or goggles when soldering or brazing.
Tubing systems that require disassembly are usually joined with threaded connectors. These may be either flared or flareless fittings. Various tools can be used to flare tubing, but a properly made flare is essential for a tight connection. Flareless fittings rely on a ferrule inside the body to bite into the tube & form the seal.
Because tubing is not rigid, long runs of unsupported tubing tend to sag. The use of clamps & other types of tubing support reduces the excessive strain put on fittings & bends. Properly placed tubing supports provide a simple & inexpensive means of preventing premature tubing failure.
Lesson 3 HYDRAULIC TUBING SYSTEMS
The maintenance of hydraulic tubing systems requires a knowledge of some basic hydraulics terminology. This lesson reviews such concepts as force & pressure, & describes the procedures for calculating these factors in a hydraulic tubing system.
Oil is probably the most commonly used fluid in hydraulic circuits. All hydraulic circuits consist of at least four major components a reservoir that contains the fluid supply, a pump that conveys the fluid from the reservoir to the system, a valve that controls the flow of the fluid, and an actuator that converts the energy of the moving fluid into mechanical work.
Always inspect the power package, the actuator, the tubing itself, & such line accessories as valves, filters, & strainers before installing a hydraulic tubing system. Establish a regular schedule for the periodic inspection & maintenance of all hydraulic circuits. This lesson concludes by describing a number of common problems that are typical of many hydraulic tubing systems. Use this section as a guide to some probable causes & cures for these problems.
Lesson 4 HOSE SYSTEMS
The selection of which type of hose to use for a given application depends on a number of variable factors. Among the most important of these are the hose ID, the nature of the material to be handled, the interior pressure and temperature, the environmental conditions in which the hose will be located, and the flexing and bending requirements of the installation.
Most plants use hoses to transport steam, water, air, & hydraulic fluids over short distances. Each application must be analyzed individually, & a hose must be selected which is compatible with the system specifications.
Fittings may be permanent, which usually require special assembly equipment, or reusable, which consist primarily of a socket & a nipple that is threaded into the socket. When measuring a hose & fitting assembly, take into account bends, angles, & possible changes in the length of a hose.
Always exercise care in handling, cutting, & preparing hose. use water if lubrication is needed to aid in assembling fittings. Protect hose from high temperatures. Establish periodic inspection & testing procedures & follow them regularly. In this way, potential problems can be spotted before they lead to hose failure.
Lesson 5 GASKETS, SEALANTS, & ADHESIVES
The major function of a gasket is to make a tight, leak proof seal between two relatively stationary components. In piping installations, gasket is frequently located between two mating pipe flanges. Such gaskets come in a variety of shapes & sizer the one you select for a particular application will depend, among other factors, on the temperatures & pressures involved, the material being handled by the piping system, and the strength & elasticity required.
Gaskets can be bought as prefabricated units or cut from stock, using an old gasket as a pattern. Remove old gaskets carefully. Inspect the condition of the surfaces that will be in contact with the new gasket. Three surface characteristics should be considered roughness, waviness, and lay. Surface irregularities can be checked with a profilometer.
If you need to use a coating in a gasketed joint, make sure the coating is chemically compatible with the substance in the pipeline. When tightening the joint, remember to always use a torque wrench & to tighten flange bolts in the proper sequence (to avoid uneven loading).
Gasket ropes, tapes, & strips are sometimes used in place of gaskets or in conjunction with gaskets. Make sure the surfaces to be joined are clean & free of defects. Sealants & adhesives can also be used to improve the quality of gasketed joint. Select sealants & adhesives on the basis of the operating conditions to which they will be subjected.

---

Ketersediaan

Informasi Detail

Judul Seri

-

No. Panggil

532.54 TPC

Penerbit

U S A : TPC Training System., 0

Deskripsi Fisik

84 hal.gmbr 29 cm

Bahasa

English

ISBN/ISSN

.

Klasifikasi

532.54

Tipe Isi

-

Tipe Media

-

Tipe Pembawa

-

Edisi

1

Subjek

Pipa

Info Detail Spesifik

Mechanical Maintenance Applications

Pernyataan Tanggungjawab

-

Versi lain/terkait

Lampiran Berkas

Komentar

---

Anda harus masuk sebelum memberikan komentar