The snippet below is from Standard Z317 - Special Requirements for Heating, Ventilation and Air Conditioning in Health Care Facilities
Can anyone provide a definition of what 'interlocked' means? The standard itself does not define it.
I understand that the intent of this interlock is to...
Hey everyone,
I keep hearing that within a dry sprinkler system water needs to be delivered to the inspector test valve within 60 seconds. However, I cannot seem to find this referenced in NFPA 13 or NFPA 2. I see some 60 seconds references within NFPA for combined dry and preaction systems...
Hi All,
We have a very long 8" diameter pipe that contains lots of twists and turns and the end of which is open to atmosphere. The pipe is normally empty, but it acts as a large discharge pipe from a tank. The tank discharge has a butterfly valve and when the tank is emptied, water flows...
Hi Everyone,
I am aware of a situation where an open to atmosphere Fire Water Storage Tank installed in a mechanical penthouse (not rooftop) of a building overflowed. It overflowed because a float switch failed to close. The overflow went into the mechanical room, flooded it and caused damage...
Hi Everyone,
As the thread subject says, I'm hoping to get some recommendations for a coating to coat a concrete force main and protect it from H2S gas produced by bacteria in the sewage. I expect H2S gas levels of around 400 ppm Past experiences/stories would be appreciated and names of...
Hi Everyone,
I have an underground water main that is quite old. It is an 8 inch diameter ductile iron pipe and is approximately 200 ft long. Wanting to see if it is still fit for service, we pressurized it to 150 PSI and left it over night. Next day, we lost 25 PSI. So 25 PSI loss over 24...
Hi Everyone,
I'm using a Dri-Prime Pump (close-coupled centrifugal pump with vacuum priming compressor) and I am using it to suck (and then pump) water out of a water storage pond at approximately 1000 GPM through a 12 inch PVC pipe. The pond is deep and has plenty of water, the pipe inlet...
Hi Everyone,
So I have a system where a building is boosting the domestic cold water from the incoming city pressure up to the 30th level. For this we have some booster pumps (standby and lead) which boost the pressure so that at level 30 the pressure is around 60 PSI. To get 60 PSI on level...
Hi Everyone,
Does anyone have any understanding or experience with why the NFPA choose such a large temperature gap between the max ceiling temperature allowed and what the "ordinary" sprinkler head can provide? Same goes for all sprinkler classifications and their MAX ceiling temperature...
Afternoon Everyone,
I have a general question about Tg (Glass Transition Temperature) and using it as a design criteria.
I come from the metals world and I tend to specific/use metals in temperatures where they will not be brittle. Metals, like plastics, tend to have a temperature above which...
Hello Everyone,
I have a random question for everyone, am looking for flow sensors that can be placed on the outside of a pipe so that I can measure flow within non-intrusively... Something similar to this: http://www.globalw.com/products/fm500.html#Options
However, I do not want to spend...
Hey Everyone,
I have what I think should be a relatively simple problem, unfortunately I cannot find a good formula to help me do the calculations. Each formula I find does not resonates well in my head because I can't seem to grasp the basic principals..any input would be greatly appreciated...
Hello Everyone,
I am not an expert on this subject, just interested, and I have a question which I am not exactly sure how to Google. I wanted to throw out what I think should be an easy question to people in the field in hopes that I could get some information on where to look for additional...
Hi All,
I have a boiler that has aluminum heat exchanger plates. I have treated water in my recirculating heating system that matches relatively well with the conductivity and the pH specifications that were set out by the manufacturer of my boiler. The one thing that is off however, is the...
Hi All,
I am oversimplifying the set-up that I have, however I'm hoping for a simple answer.
I have a tank that is pressurized with water, lets assume the tank only has an outlet and is closed off to the atmosphere. If I draw water from this tank from the outlet at some rate, what sized vent...
Hi All,
I have a question that I'd like to get some feed back on.
I've looked through codes/standards of various municipalities regarding the type of materials that can be used for water main lines. They all share the typical ones:
1. Ductile Iron
2. Concrete
3. PVC
However...
Hi All,
So I have a cylindrical liquid storage tank that sits horizontally. Due to pitting corrosion, a small section of the tank (the pit about 1/8 inch in size) reduced the wall thickness of that tank locally. I essentially have now a tank that is of uniform thickness except the area where I...
Hi All,
A new water main is being put into a subdivision and a chlorine retention test will be performed apparently. I cannot seem to find a good idea of what this test is all about. Can someone point me in the right direction so I can understand what will be performed?
Thanks in advance!
Hello All,
I was wondering if anyone had a good source for where I could find stress intensity factors for a tube (similar to a pipe) loaded in bending.
I have a tube which failed for me and I noticed that it was initiated by fatigue failure. Fatigue failure produced a flaw within the...
Hi All,
I have a pipe (a long hollow cylinder open on both ends) which I would like to flatten into something that will look like two flat sheets (theoretically). I want to find a formula which I can use to calculate how much force it would take to flatten my pipe by applying an external...
