Discuss NFPA CFPS Exam Topic 4 Question 13

The typical discharge coefficient of a solid stream nozzle for a standard orifice with sharp edges is?

A0.62

B0.75

C0.8

D0.95

Suggested Answer: A

. 0.62

The discharge coefficient of a solid stream nozzle for a standard orifice with sharp edges is a dimensionless number that indicates the ratio of the actual flow rate to the theoretical flow rate of the nozzle. The discharge coefficient depends on the geometry and the flow conditions of the nozzle.the typical discharge coefficient of a solid stream nozzle for a standard orifice with sharp edges is about 0.62, which means that the actual flow rate is about 62% of the theoretical flow rate. This value is based on the experiments conducted by the National Bureau of Standards (now NIST) and reported in the paper ''Discharge Coefficients of Fire Nozzles'' 1. The paper also provides a formula to calculate the discharge coefficient for different nozzle diameters and pressures123

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25 comments · newest first

Rosann 10 months ago

0.95 seems way too high for a sharp edge orifice!

Tu 10 months ago

I thought it was higher, like 0.75?

Becky 10 months ago

Totally agree, 0.62 is the standard!

Kathrine 10 months ago

Wait, are you sure it's not 0.8? That sounds more right.

Chantell 11 months ago

It's usually around 0.62 for sharp edge orifices.

Sena 11 months ago

I’m leaning towards 0.95, but I can't recall if that applies to a different type of nozzle.

Alpha 11 months ago

I feel like 0.8 is too high for a sharp-edged nozzle. I might go with 0.62 since it sounds more familiar.

Mohammad 11 months ago

I remember practicing a similar question, and I think 0.75 was mentioned, but that seems a bit high for a standard orifice.

Jordan 12 months ago

I think the typical discharge coefficient for a sharp-edged orifice is around 0.62, but I'm not completely sure.

Sonia 12 months ago

This seems straightforward. The discharge coefficient for a sharp-edged orifice is usually around 0.62, so I'm confident that A is the correct answer.

Salena 12 months ago

I'm a bit unsure about this one. I know the discharge coefficient depends on the geometry of the orifice, but I can't quite recall the typical value for a sharp-edged orifice. I'll have to think it through carefully.

Josefa 1 year ago

Okay, I think I know this one. The discharge coefficient is usually lower for sharp-edged orifices compared to rounded ones, so I'm going to go with A - 0.62.

Yuonne 1 year ago

Hmm, this looks like a fluid mechanics question. I'll need to remember the formula for discharge coefficient and think about how the sharp edges of the orifice would affect it.

Geraldine 1 year ago

I'm not sure, but I think it's B) 0.75.

Merri 1 year ago

I remember reading that the typical discharge coefficient is D) 0.95.

Casandra 1 year ago

I disagree, I believe it's C) 0.8.

Joye 1 year ago

I think it's A) 0.62.

Elenora 1 year ago

Ah, the joys of fluid dynamics. It's like trying to herd cats, but with water instead of felines. I'm feeling bold, so I'll go with D. Who knows, maybe I'll surprise myself.

Herman 1 year ago

↳ replying to Elenora

User 2: I'm feeling bold too, I'll choose D) 0.95

Vernice 1 year ago

↳ replying to Elenora

User 1: I'll go with A) 0.62

Yuriko 1 year ago

Discharge coefficients, the bane of every engineering student's existence. But hey, at least we get to play with water and pretend it's work! I'll go with B, just to keep things interesting.

Gianna 1 year ago

Ah, the age-old question of discharge coefficients. If only we could discharge our exams as easily as water through a nozzle, am I right? I'm going to have to go with C on this one.

Rikki 1 year ago

Hmm, I remember learning about discharge coefficients in my fluid mechanics class. If I recall correctly, the sharp-edged orifice should have a lower coefficient than a rounded one. I'm going to go with option A.

Celia 1 year ago

↳ replying to Rikki

I agree, let's go with option A.

Glen 1 year ago

↳ replying to Rikki

I think you're right, option A seems like the correct choice.

NFPA CFPS Exam - Topic 4 Question 13 Discussion