These design guidelines are for the utility distribution systems that are in tunnels, direct buried piping, and trenches, that are located on yale property and in the city streets. The material progresses from simple to more difficult topics. Direct buried conductors and cables shall be protected from damage in accordance with 300. Utility distribution systems iowa state university. Leaking pipes in the steam tunnels and leaking piping or valves in manholes are easily detected since visible steam will. Steam piping transports steam from the boiler to the end. Carrier system design manual part 1 load estimating. Yale university steam and chilled water utilities design guidelines e.
Duct and conduit 475 ductility tough, pe conduit will better resist brittleness with age or cold weather. Basics for stress analysis of underground piping using. Propane gases steam boilers heating contractor address phone number boiler model number boiler serial number installation date warning see warning on page 3 for liquefied. Steam tracing is usually accomplished by running steam lines in direct contact with the piping or vessels to be heated. Rotary vacuum drum filter valves, piping, expansion loops, and other equipment should be installed in such a way as to prevent the formation of vapor pockets. The university owns and operates district steam distribution systems on the north, centra l, centennial, and west precincts for heating and process loads. Use of a conduit system for utility piping must be approved by upe. Piping shall be installed at the locations shown on the construction drawings, properly. Expansion loops consist of rectangular loops formed by using 90 angle bends figure 10. The quality of steam entering the heater can have a direct impact on the heaters performance and frequency of maintenance intervals. Basics for stress analysis of underground piping using caesar.
Steam piping systems are preinsulated with mineral wool or calcium silicate insulation and jacketed with an epoxy coated steel or double. Do we need an expansion loop or something else for an insulated direct buried underground carbon steel piping. Steam system design and best practices related to kiln drying. Underground heat and chilled water distribution systems govinfo. For typical pressure piping applications, the pipe demand calculations for some of these load. Piping should be supported so that strains are not placed on the filter or its auxiliary equipment, and flexible connections should always be used where the piping. How to bury steam lines if you have to heating help. A boiler furnishing steam at pressures not exceeding 15 pounds per square inch. At project closeout, submit record drawings of installed piping and piping products, in accordance with requirements of section 15000. The overwhelming majority of steamtraced piping systems employ external tracing. Steam piping systems are preinsulated with mineral wool or calcium silicate insulation and jacketed with an epoxy coated steel or double jacketed with an inner steel conduit that is contained in an outer hdpe jacket. Carrier steel pipe is manufactured acc en 102162 or another equivalent norm regarding seamless pipes, steel grade p235gh. These guidelines also apply to major distribution piping that travel through buildings typically found in basements or crawl spaces.
Each of these options has a direct benefit on the longterm operating costs of the. The difference between piping codes and piping standards can be summarized. Heat tracing of piping systems effective steam tracing wermac. However the term buried piping or underground piping, in a true sense, appears for. In many cases steam systems were designed long before there was any concern about energy efficiency. Design alert reinsulating direct buried steam and. Master specifications division 23 heating ventilating and air. Duct and conduit 473 chapter 14 duct and conduit introduction. This standard is intended to provide useful information to the professional service provider psp to establish a basis of design. Three, section 27 thrust restraint design for buried piping. Directburied conductors and cables shall be protected from damage in accordance with 300. Expansion loops should be installed in the horizontal plane and pockets should be avoided.
Distribution is through a system of underground walkable tunnels or direct buried piping systems. A typical expansion loop for use in hot piping systems is shown in figure 10. It includes instructions for the proper drawing of symbols for fittings, flanges, valves, and mechanical equipment. This allows the reader to begin anywhere in the manuals depending on the individuals background. Guidelines for the design of buried steel pipe july 2001. Bonding the permanent joining of metallic parts to form an electrically conductive path and continuity to safely conduct any current likely to be imposed. Steam traps are used to remove condensate from steam headers, steam. These quick check formulas are dealt with in detail in chapter 19 of this book. Pipe drafting and design, third edition provides stepbystep instructions to walk pipe designers, drafters, and students through the creation of piping arrangement and isometric drawings. Low pressure steam, high pressure steam, steam condensate, domestic hot water, domestic hot water return and compressed air. Find all the books, read about the author, and more.
F as compared to other materials conditioned at 73. Direct bury underground steam piping shall be permapipe multitherm 500 or equal, preinsulated piping systems, consisting of an extra strong class, black steel. For direct burial preinsulated piping system for centralized district heating preinsulated pipe for direct burial. For plant piping system project standards and specifications page 3 of 19 rev. Guidelines for the design of buried steel pipe july 2001 page 2. Directfired energy directly transfers the heat of fuel com. Underground or buried piping or pipeline is all piping that runs below grade. En 102171 another equivalent norm regarding longitudinally welded pipes, steel grade p235tr1tr2. Piping always pitched in the direction of flow use of eccentric reducers to eliminate creation of condensate collection points low spots in piping use of separators to eliminate wet steam proper drip trap stations in all required locations use of air vents at all endofmain locations make steam main branch takeoffs from top of pipe. A significant portion of the steam and condensate piping is installed in steam tunnels.
These utility systems are operated and maintained by the upe tunnels department. District heating and cooling system piping for steam. Piping for the transport of chemicals, which provides chemical resistance data for pe with a wide range of chemicals. Multitherm 750 supreme introduces nanotechnology to underground district heating piping. The flow of steam is typically much faster in steam distribution piping than in equipment and can reach speeds of over 30 ms 100 fts. The steam tunnels allow utility staff to access the piping for maintenance. In every process industry, there will be few lines sewer or drainage system, sanitary, and storm water lines, firewater or drinking water lines, etc, part of which normally runs underground. A code has a limited jurisdiction defined by the code. This is illustrated by impact testing on pe conduit conditioned at 4. Piping shall be new, full weight, and of sizes shown on the drawings.
Best practices for condensate removal on steam lines tlv. There is also approximately one mile of direct buried steam line, primarily located on the southeast portion of campus serving the richardson court association residence hall area and the iowa state center. Although many directburied power cable systems are designed for 30 or 40year lifetimes, they are susceptible. The design sizing of such piping requires significant specialization because condensate recovery piping collecting from steam traps must be designed for twophase flow. A wide variety of plastic steam pipe options are available to you, such as hot rolled, erw, and cold drawn. Permapipe manufactured state of art pre insulated piping system are in wide use for transferring steam by direct buried piping network for district heating networks in cold counties viz america, canada. The multitherm 750 supreme is the first preinsulated piping system fortified with aerogel nanotechnology for the most advanced and thermally efficient steam and hot water transportation piping system. The lost art of steam heating paperback january 1, 1992. Low pressure steammodels gxh230 through gxh300h low pressure steammodels gxha100 through gxha200 galaxy gasfired cast iron boilers for natural and l. The primary advantage of an expansion loop is that it is pressurebalanced.
The piping mto or material takeoff is a list of all the piping items required to purchase to fabricate and construct the design. However, the majority of the steam piping is direct buried. Turn up a normac riser meter kit at either end if need be where the pipe must come up through the grade and capable of being damaged. Good practices for gas piping and appliance installations. Exterior steam and condensate lines shall be installed, in order of preference, in fully accessible walkable concrete utility tunnels, semiaccessible precast concrete tunnels, or shallow trenches.
This book is an excellent source of information on buried pipe analysis and design from theory to application. Steam systems should be piped to allow gravity draindown when not in use, or should be blown out with compressed air at the end of each heating season. Underground directburied piping systems chilled water, hot water, steam this specification has been prepared by pittsburgh corning corporation using generally accepted and appropriate technical information, but it is not intended to be solely relied upon for specific design or technical applications. Where the enclosure or raceway is subject to physical damage, the conductors shall be installed in rigid metal conduit, intermediate metal conduit, schedule 80 pvc conduit, or equivalent. Distribution of campus steam, condensate and high pressure steam drip. These direct buried piping systems are also used for injecting steam in oil wells to raise reservoir temperature for steam assisted gravity. If this condition occurs on the pipeline, provide a. Boiler horse power one boiler horse power equals approximately 42,500 btu input. Low temperature impact resistance pe withstands low temperature impact better than any other material.
These materials are capable of withstanding elevated temperatures and provide a waterproof barrier between the carrier pipe and. In most cases, the cold spring technique is applied. Locate the valve next to the tee on all fire hydrant leads and restrain all. The piping used to transport condensate is typically called condensate recovery piping or condensate return piping. Thanks to duane hagen of merlo steam for providing these photos and an explanation of what the problem is and the best way to fix it. The underground steam piping systems we engineer at insulpipe systems are designed to all ashrae standards and feature drainabledryable class a insulated or standard epoxy coated steel jacketed systems. A pipe designed to carry pressurized steam from a boiler to the working components, i. Duct and conduit energy piping systems conduit division. View post link to a brief introduction to the oil and gas industry. Fundamentals of buried pipe analysis and design are clearly presented as well as information on nonlinear finite element analysis of soilstructure.
Piping codes defines the requirements of design, fabrication, use of materials, tests and inspection of pipes and piping systems what you need to do. The need for an expansion loop in underground piping may be unnecessary if most of. At these speeds, when the crosssectional area of a pipe section is completely filled by water, slugs of condensate can be carried through the piping at high velocity causing water hammer, which can cause. West campus precinct the university owns and operates district steam distribution systems on the north, centra l, centennial, and west precincts for heating and process loads. In contrast, a direct buried piping system consists of steam andor condensate line with insulation installed within another thinner pipe. The acceptability of direct buried underground heat distribution uhd systems is determined according to the performance standards contained in the federal agency prequalification procedure. Just because its been that way for a long time, dont assume its right. Such piping usually includes valves to control the routing of the steam, or to stop the flow altogether. The threephase initiative will replace all remaining direct buried steam distribution piping with a more reliable and efficient tunnel system.
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