I have a case where we will build a building that requires 100% OA for process purposes. There is a requirement for 2 air changes per hour. The building is a typical metal building used in the US, and will be insulated. There will be about 10 people in the building normally, and some...
I have a question about management programs for Relief Valves around the use of spare valves. For example, we have three identical locations for relief valves in the same service and 5 total valves. Threee relief valves are in service and two spares. When the calibration is due on one of the...
Has anyone done any calculations to show what happens when an atmospheric storage tank is drained without venting? We have had several issues with this lately. One involved steam and we are sure that was related to the vacuum created when the steam condensed. The other was when a tank was...
I am evaluating some existing filters that use swing bolts and lugs atttached to the filter body that are used to connect the filter head. The swing bolts pivot on a pin up to lugs welded to the head. The filters are designed per ASME Section VIII, Div 1. The swing bolts and lugs are equally...
Does anyone have an equation from the Pressure Vessel Research Council for gasket seating stress? I have looked at a couple of references and have found a couple of equations that do not match.
Thanks for the help.
I have a situation where I need to reduce the pressure from a supply header where a pump takes its suction. With the current supply pressure and the pump inline, the discharge pressure from the pump exceeds the pressure rating on the heat exchanger in the system. I can't remove the pump...
Does anybody have any suggestions on how to control cooling tower leaving water temperature to +/- 1 deg F? We have a two cell tower, each fan has a VFD, and the tower serves about 50 smaller closed loop water systems cooling process loads. Our operation currently is up and down, so process...
We have had a couple of leaks in remote areas of our chill water systems that went undetected for a while because there is no way to check every area all the time for leaks. I was thinking of installing a flow meter and some kind of timer in the water make-up line to the closed loop chill water...
What is the concensus on how to control flow (chilled water and condenser water) through a chiller? The system I am referring to is a multiple chiller system, primary secondary pumping, with a common supply header for the chill water and condenser water, in other words, the pumps are not...
Can anyone recommend a good source of information for the design and thermal analysis of cooling towers? I have looked at some of CTI's info but I wanted some input before buying it.
Has anyone seen a bearing failure on a rooftop air handler supply fan that is related to airflow problems? We have a McQuay air handler with a return and supply fan and have had several failures of the drive bearing on the supply fan. About four months ago an energy recovery ventilator was...
Has anyone seen a bearing failure on a supply fan in a rooftop air handler that was related to airflow problems? The situation we have is a failure on the drive bearing of a Mcquay air handler. This unit also has a return fan. On the outside air intake, this unit was tied to an energy...
I am looking for input on the use of spin-ins, scoops and air extractors in branch take-offs in low pressure ductwork. We don't use them generally, but I see them called for on alot of projects designed by other engineers. My feeling is that they restrict airflow and cause greater friction...
Can anybody give me some information on what types of controls are required for a Class 10,000 cleanroom? I'm sure of temp and humidity controls, but what about monitoring, room pressurazation, air flows etc.? Is there anywhere I can find this information? We are using standard package units...
In a two pipe heating system, if I have a two row coil should the fluid inlet be on the inlet to the first coil in the direction of the airflow or the second coil? I have seen it both ways. Any suggestions?
