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Thanks Latexman, Biggest thing I was asking if I used the steam pressure drop formulas, what density would I use for the steam. Would I just be conservative and use the density of 14.7 PSIA steam? Although the API 521 method looks better since it works backwards and we know the pressure and...

Hello, We have a PSV that has a set pressure of 50 PSIG, 10% allowable accumulation, and 4,456 lbs./hr. relief capacity. I'm looking to size the tailpiece piping to ensure we don't go over the 10% rule (5 PSI in this case) for the relief valve. If I use normal pressure drop calculations, what...

They do not want to remove the 6" steel line. They want to install a 4" HDPE pipe in the 6" steel pipe. It is all related to cost The person recommending the job thinks the steam tracing (that has no temperature control) will never heat the pipe inside the steel pipe to 120 degrees F. This...

Folks, Our plant is looking for an option to put a 4" HDPE pipe in a 6" carbon steel line. The 6" carbon steel line is currently in service. They want to reutilize the 100 PSIG steam tracing on the outside of the pipe. My main concern is the HDPE piping only has a rating of 140F and the 100...

We are looking to install. A wet steam accumulator on our boiler system. We are struggling on level control. I read that the steam entering the vessel refills the vessel water that is flashed off. But someone we visited had a water pipe going into the accumulator from the deaerator. Do we need...

Hello, I'm looking to have someone double check my calculation for the capacity of a 250 BHP boiler assuming: Feedwater Temperature = 270 degrees F (Specific Enthalpy of the Liquid = 239.17 BTU/lb) Steam Pressure Desired = 250 PSIG (Specific Enthalpy of Liquid = 381.76 BTU/lb, Latent Heat of...

Thanks for the reply. I'll have to look at my Crane book. I have the newest version and could not find it. I made the comment since I thought if you had a regulator that dropped pressure from 100 PSIG to 3.5 inches W.C. you would need less piping of a certain size to get the target flow there...

Hello, Is there any way to convert a Cv or Cg for a pressure regulator for compressible flow to a resistance coefficient in pressure drop/flow calculations? Or do you just have to do the following: - determine the pressure in the pipieline up to the regulator - determine the pressure drop of...

Hello, Is there a rule of thumb on how much temperature rise you would expect in a deaerator for boiler feedwater to and from the deaerator? I'm assuming some of the heat from deaeration gets transferred to the incoming feedwater. Thanks in advance.

Thank you for the replies. The reason for the calculation is that we are changing our emergency dump piping for one of our polystyrene reactors. The piping is going to be 6" schedule 40. I know the power law variables and the temperature and material. I was just confused when the Ron Darcy...

Hello, I am researching how to calculate pressure drop of a non newtonian (power law) fluid when it is in the turbulent flow regime. I read the "Facts at Your Fingertips" for Fluid Flow in Chemical Engineering magazine (December 2008) to calculate the friction factor for power law fluids. I...

Thanks everyone. The reasoning behind this is that we had a PSV discharge line freeze that discharges into this tank. The PSV discharges from the tube side of a shell and tube heat exchanger back into the tank. We have a flow switch on this discharge line that has not alarmed and it is...

Thanks for the replies. This is an expansion tank so I forgot to mention that some of the pressure increase is due to the volume change of liquid from 20C to 110C. The tank starts with the 5 PSIG pad at 20C, then the solution is heated to 110C. Thanks.

Hello, I'm trying to figure out the vapor composition in our expansion tank. The solution is a 30% propylene glycol solution (by weight) and it is at a temperature of 110 degrees Celsius. The total pressure in the tank is 26 PSIG. There is a 5 PSIG nitrogen blanket on the tank too. My...

Thanks for the response. So if I have 100 kg of 40% by weight HCL (40 kg HCL) and dilute it to 25% HCL, from your chart I would get a heat generation of: (427-374)*40 = 2120 kcal. Correct?

Hello, Anyone have a good procedure or calculation method for calculating the heat generated from adding water to 37% by weight Hydrochloric Acid. I've seen the enthalpy-concentration diagram in Perry's but don't have much experience with this. For example the heat rise of adding 100 gallons...

Thanks everyone for your input. Learned a lot after reading these posts. I did look to the affinity laws and saw that flow and impeller diameter is a 1:1 ratio. So if I want to cut flow from 635 GPM to 450 GPM, I would need to cut the diameter of the impeller 70.9% (450/635*100). We...

Thanks for the replies. Can one of you give me a technical reason why measuring the pressure after the valve is what I need and measuring it before the valve is incorrect? Need to understand this concept more about centrifugal pumps. Thanks!

We have a centrifugal pump that is pumping too fast for our process. The medium is water and currently it is pumping at 635 GPM. We need it to pump 425 GPM of water to our reactor. Our maintenance staff wants to trim the impeller instead of just throttling back a valve in the discharge line...

TD2K - I got the U value from the coil vendor. Srfish - Can you show me on the internet where one of these charts are? I have the Process HEat Transfer Book from Donald Kern but can't find a chart in there. Thanks.