Hello
What is the insulation type used in the photo attached (pipe and valve)? I am just curious.
Thank youhttp://files.engineering.com/getfile.aspx?folder=bc0c536b-e62b-4f91-88e2-9381a261e957&file=1399978746735.jpg
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When it comes to hydraulic calculations for a chilled-water loop how is the safety selected? This is for the purpose of sizing the recirculation pumps for a twenty storey tower.
I wanted to learn how to use software for these calculations but found that it is more important to start...
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I came across HVAC air-handler specifications that describe the outer part of the unit casing made from 'zincated steel sheets'. I never came across zincated steel before but I understand so far that it has something to do with nickel plating and nothing to do with protecting the...
With reference to the subject title, I did not understand a passage in the SMACNA Duct Construction Standard Metal and Flexible, Second Edition, page 1.63:
Joint [...] T-12, STANDING S: When using S on all four sides, fasten the slip to the duct [...] at 12" (305 mm) maximum intervals.
I...
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My project specifications call for painting the visible internal portions of duct outlets in dull black. Unfortunately I have no further details regarding this paint. I am concerned about the impact this paint can have on the health of the occupants because these are ventilation ducts...
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Can anyone tell me how equation (2) was derived in the following article? The equation is regarding the wire-to-water efficiency of a multiple pump, constant speed pumping system. I am not sure how the pressure-head ratio fits in. The product of the pump and motor efficiency is...
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I came across the following paragraph in a pumping handbook (vibration and noise. (1998). In pumping station design (2nd ed.). butterworth-Heinemann. ) regarding hydraulic loads imposed on pump casings due to improper installation of flexible joints at pumps nozzles for pipes equal to...
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For centrifugal circulator pumps operating in parallel, isn't important to be able to verify the flow for each pump individually?
I know that given the pressure gauge readings and the pump curves the flow can be determined but I'm asking about verification of flow of each pump while...
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I came across the below statement in a HVAC pump handbook regarding TEFC motors. Can anyone explain please?
"Totally enclosed, fan-cooled motors are available for applications where the motor is wetted periodically. It should not be used for
routine motor applications in this...
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I was searching for field inspection software for my Android phone after a friend showed me a list of software on his iPhone. There is a good amount of free ones that organize photos, markups, drawings, have team collaboration tools, and help in generate reports. Does anyone in the...
Greetings All
For uPVC drainage pipes and fittings to BS EN 1329, are there any chemicals that can be flushed down the toilet that can weaken the pipes/fittings? Many things can be flushed down the toilet but I had the peculiar experience of a specific soil riser, in a residential tower, that...
I already posted this in the HVAC/R forum but received no replies so I am re-posting here.
The below inquiry is regarding valves for a commercial building chilled water piping system (i.e. clean water @ 4'C with rust inhibitor chemical).
For large chilled-water pipes, dia 200-350mm, what type...
For large chilled-water pipes, dia 200-350mm, what type of isolating valves would you use?
I am aware of the differences between butterfly and gate valves; namely the price, size and weight, but I am concerned that butterfly valves shut-off too quickly (I read that for large valves the last 20%...
With reference to SMACNA Duct Construction Standard, in page 20 of Appendix A under the heading: 'Sample Shop Standards for 2" W.G. Pressure Class what are the 'brake shop' and 'coil line' referred to in the tables? Why are there separate tables for each?
Also how can a zee channel/bar be used...
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I saw this video about ram pumps and it seems like a very good idea to apply to a drainage sump pit in a commercial building.
video link: http://www.youtube.com/watch?v=wfgnvyLiboU
However, I have never seen such an installation. I only have experience with centrifugal submersible...
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For grease (kitchen exhaust) ducts, can intumescent coating be used on the outside of of the duct instead duct wraps like Fyrewrap? How much clearance to combustibles will be required if that is the case? This is for compliance with NFPA 96.
Much obliged for any information.
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Is the attached control scheme (excerpt from handbook, see section 9.10) also known as pressure independent and auto balancing control valve (PICV) or am I mistaken?
Much obliged for any information.
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Is it mentioned anywhere in ASHRAE where to provide sand trap louvers? We provide them on all fresh air intake but are they also neccessary for stair pressurization as well (project is in a desert country)? I know the ASHRAE 52-76 method of testing standard describes tests for...
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I encountered a design that has a the shaft exhaust duct riser sharing the same fire-rated enclosure with other ducts. I know this is not allowed by code. There is no space to provide a partition. The duct will be coated with an inumescent coat. I am not sure if this will provide...
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NFPA 96 states that kitchen exhaust ducts shall not pass through fire rated walls. Also NFPA 90A advises against using the same shaft enclosure for kitchen exhaust and other HVAC ducts. I want to understand the reasoning behind this.
My argument is against engineers that claim a...
