THERMAL INSULATION REQUIREMENTS FOR MANHOLE DESIGN Kathie Leonard Auburn Manufacturing, Inc. and Gordon Hart, P.E. Artek Engineering, LLC IDEA Annual Conference Indianapolis, Indiana June 15, 2010 1 PRESENTATION GOAL: Address the Need for Thermal Insulation in Manholes A Fact Finding Session 2 WHYWE ARE HERE • Manufacturer (AMI) and Consultant (ARTEK) on Insulation Systems • Demonstration Projects • IDEA Steam Distribution Workshop – Reno 2/ 10 WHYYOU ARE HERE • To provide feedback on applications and performance requirement of manhole insulation needs. 3 Why is Thermal Insulation Needed in Manholes? In other words…what made us realize that we need to address this subject, anyway? 4 Why is Thermal Insulation Needed in Manholes? • Piping and piping components found beneath manholes • The manhole covers themselves 5 What is Unusual About the Manhole Environment? • • • • • Confined space Sometimes floods Frequently very humid Experience steam leaks Difficult to insulate piping components • Cramped working conditions 6 Why Do We Care About the Manhole Environment? • Manhole covers can pose a health & safety problem if overheated • Maintenance personnel need to enter manholes • As ‘confined spaces’ manholes can pose safety concerns for maintenance personnel 7 List of Insulation Exposure Requirements • • • • • • • • Continuous 415°F steam service temperature Submergence under water Steam environment ( hot, high humidity – 300°F, 100% RH) Sometimes cool, high humidity environment Dripping water Dripping oil from road surfaces Road salt and other corrosive chemicals Some physical abuse 8 Insulation System Options – Piping Components • Rigid, preformed insulation (fiber glass, mineral wool, perlite, calcium silicate, cellular glass, etc.) • Flexible blankets (fiber glass batts, glass fiber mats, HT fiber mats, aerogel mats, flexible elastomeric sheet.) • Pre-engineered removable/ reusable blankets with coated fabric • Site-cut removable/ reusable modularized blankets with coated fabric 9 Insulation System Options – Piping Components 10 Insulation System Options – Piping Components Fiber glass pipe insulation with ASJ Calcium silicate pipe & block insulation 11 Insulation System Options – Piping Components Preformed rigid pipe insulation with metal jacketing (calcium silicate with aluminum jacketing) 12 Insulation System Options – Piping Components Preformed rigid pipe insulation with metal jacket Source: National Commercial & Industrial Insulation Standards Manual-MICA Plate #12 13 Insulation System Options – Piping Components Fiber glass elbows with PVC or metal jacket Source: National Commercial & Industrial Insulation Standards Manual-MICA Plate #12 14 Insulation System Options – Piping Components Calcium silicate pipe & block insulation (rigid) 15 Insulation System Options – Piping Components Flexible elastomeric sheet 16 Insulation System Options – Piping Components Flexible elastomeric sheet covered with lagging cloth and a vapor retarder mastic 17 Insulation System Options – Piping Components Fiber glass pipe and tank wrap 18 Insulation System Options – Piping Components Flexible aerogel insulation 19 Insulation System Options – Piping Components Pre-engineered removable/ reusable insulation blankets National Commercial & Industrial Insulation Standards Manual-MICA Plate #47 20 Insulation System Options – Piping Components Pre-engineered removable/ reusable insulation blankets 21 Insulation System Options – Piping Components Removable/ reusable modular insulation. Measured and cut from rolls at the job site. Photo Courtesy: EverGreen®Cut n’ Wrap 22 Insulation System Options – Piping Components Removable/ reusable modular insulation. Cut from rolls at the job site. Attached with hook and loop fastener strapping Photo Courtesy: EverGreen®Cut n’ Wrap 23 Insulation System Options – Piping Components Multi-ply laminate jacketing over preformed rigid pipe insulation 24 Insulating Manhole Covers Objective: To keep the covers from becoming sufficiently hot to burn people Method: To prevent the cover’s external temperature from exceeding 130°F (excluding the effects of sunlight) Concern: Steam leaks within the manhole and conduction heat losses from bare pipe components 25 Insulating Manhole Covers Environmental Conditions: Manhole ambient temperature of at least X°F and outdoor ambient temperature of Y°F with a wind speed of Z mph. Problem: If we know the values of X, Y, and Z, then we can solve the heat transfer problem and determine the minimum thickness of insulation required for a given type of insulation. 26 Insulating Manhole Covers General Insulation System Requirements • • • • Keep out steam & water Maintain thickness Be durable Either remain attached to cover or be detachable • Other? 27 Insulating Manhole Covers Results of Heat Transfer Calculation 3E Plus® • • • Manhole temp = 300°F Ambient conditions of 90°F, 0 mph wind Insulation type: glass fiber felt (ASTM C1086) • Cover: Zero permeance multi-ply laminate with an emittance = 0.0 • Solution: Required thickness to keep temp < 130°F = 1.0 inch 28 Insulating Manhole Covers Questions • Are these assumed conditions reasonable? • What other design parameters should be considered for manhole cover insulation? 29 What Might the Insulation System Requirements Be? • Either to remain dry at all times or be able to dry without damage • To maintain thickness • To cover all pipe components (exclude valve wheels) • To exclude water vapor & liquids • To be removable/ reusable on valves, flanges, & other such components 30 Manhole Piping Insulation Systems Questions • Is this a complete list of insulation system requirements for manhole piping? • Is this a complete list of insulation material solutions? 31 THERMAL INSULATION REQUIREMENTS FOR MANHOLE DESIGN Thank you… Visit us at AMI at Booth #34 Contacts: [email protected] [email protected] 32
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