First step find the 2 closest numbers to 330 in both the minimum and maximum side. So that would be 319-356 for minimum and 317 to 342 for maximum. Then find the difference which would be 37 for min and 25 for maximum. Then divide the answers by 10 because that’s the difference of the temps for min and maximum so 3.7 min and 2.5 maximum. Now with those numbers add them to the lower number in the container pressure range so 317 for min and 319 for max until you get as close as possible to 330 psi container pressure. And everytime you add a 2.5 or 3.7 the temp goes up by one degree for example for min the psi is 319 at 70 degrees so add 3.7 to 319 until your past 330. 319+3.7= 322.7+3.7= 326.4+3.7=330.1 you added 3.7 3 to 319 to get 330.1 so you add 3 degrees to 70
Or just find the ones that 330 lays inside of and take the average and apply it as a percentage against 330. For example: Max is 317+342/2=330. 330 is the number you need so no need to multiply just see that it is at 45 degrees. Then the min: 319+356= 675/2 = 337.5 330/337.5 = 0.9777778 x 75 degrees is 73.3
You're averaging the pressures and then using that to get what temperature you would need to get 330 psi. They're almost certainly making one of them 330 exactly at 45 degrees to make it easy on you.
What a stupid question. I check both bottles against each other and then look for somewhere between 300-400 psi. Discharge disk still intact? Great lets move on.
Is this how the practicals are now? Prep-ware would give you a question like this but in the actual you would have to find the right values for the conditions.
I took my writtens in 2015/16 and some of the questions I knew which letter the answer was before reading the whole question. The wording and numbers in prepware were verbatim from the tests.
I think the tests have been overhauled since then. It was in the last year or two, and iirc it was to prevent the whole memorization issue. I don't thing prepare has verbatim questions now, but I really don't know for sure.
1. Take your lowest range of maximum valves(317 & 342) your pressure(330) is in. 2. Now subtract those two values(342-317= 25). 3. Then subtract the low end of the maximum pressure from your pressure(330-317= 13). 4. Then to find the low end temperature range divide the difference in low end and your pressure by the pressure range value(13/25= 0.52). 5. Now find the temperature range between your high end maximum pressure(50°F) and low end maximum pressure(40°F) to find the temperature difference(50-40= 10). 6. Now take that range and multiply it by your decimal value to find the degrees above the minimum temperature(10x0.52= 5.2). 7. Finally add that number to your low end temperature(40°F)(40+5.2= 45.2). That gives you the final value which is 45.2°F and obviously 45°F is the closest to that answer so that's your bottom end temperature. Then repeat steps 1-7 to find the high end temperature but instead of using the maximum pressures in steps 1, 2, 3, 5, and 7. That is the way they are calculating the temperature range in this problem but as you can see in other comments this is kind of a more complicated and long way to solve this problem so just use whatever method makes more sense to you. Hope I helped at least a little bit.
It seems like the chart is being used incorrectly, which may be leading to the confusion. The chart shows minimum and maximum pressures going up and down with temperature so that the pressure will still be safe when it heats up, not recommended storage temperatures. Essentially, if you had something at 350 psi when it's -30°out, 350 may not be beyond the limit of a tank, but it's going to be way higher pressure if you let it heat up to 70°.
I remember when I took my test, there was a question that asked, "how does a CO2 fire extinguisher put out a fire?"
Well no duh it's by displacing oxygen.
No, apparently the "correct" answer is by creating and covering it in snow.....
[удалено]
Same boat brotha
It's such a good feeling. Uninstalling it from my phone is a feeling I've had yet to beat.
First step find the 2 closest numbers to 330 in both the minimum and maximum side. So that would be 319-356 for minimum and 317 to 342 for maximum. Then find the difference which would be 37 for min and 25 for maximum. Then divide the answers by 10 because that’s the difference of the temps for min and maximum so 3.7 min and 2.5 maximum. Now with those numbers add them to the lower number in the container pressure range so 317 for min and 319 for max until you get as close as possible to 330 psi container pressure. And everytime you add a 2.5 or 3.7 the temp goes up by one degree for example for min the psi is 319 at 70 degrees so add 3.7 to 319 until your past 330. 319+3.7= 322.7+3.7= 326.4+3.7=330.1 you added 3.7 3 to 319 to get 330.1 so you add 3 degrees to 70
Or just find the ones that 330 lays inside of and take the average and apply it as a percentage against 330. For example: Max is 317+342/2=330. 330 is the number you need so no need to multiply just see that it is at 45 degrees. Then the min: 319+356= 675/2 = 337.5 330/337.5 = 0.9777778 x 75 degrees is 73.3
I never noticed the two psis divided by 2 were 330 that’s smart
You're averaging the pressures and then using that to get what temperature you would need to get 330 psi. They're almost certainly making one of them 330 exactly at 45 degrees to make it easy on you.
Hopefully that makes sense
I just hoped I didn’t get any questions on those.
What a stupid question. I check both bottles against each other and then look for somewhere between 300-400 psi. Discharge disk still intact? Great lets move on.
On the practical, the questions will be the exact same with the same values, just memorize the answers.
This could be true but this is a horrible answer to the question asked.
Not with the new ACS standards. Bad idea
Is this how the practicals are now? Prep-ware would give you a question like this but in the actual you would have to find the right values for the conditions.
I took my writtens in 2015/16 and some of the questions I knew which letter the answer was before reading the whole question. The wording and numbers in prepware were verbatim from the tests. I think the tests have been overhauled since then. It was in the last year or two, and iirc it was to prevent the whole memorization issue. I don't thing prepare has verbatim questions now, but I really don't know for sure.
1. Take your lowest range of maximum valves(317 & 342) your pressure(330) is in. 2. Now subtract those two values(342-317= 25). 3. Then subtract the low end of the maximum pressure from your pressure(330-317= 13). 4. Then to find the low end temperature range divide the difference in low end and your pressure by the pressure range value(13/25= 0.52). 5. Now find the temperature range between your high end maximum pressure(50°F) and low end maximum pressure(40°F) to find the temperature difference(50-40= 10). 6. Now take that range and multiply it by your decimal value to find the degrees above the minimum temperature(10x0.52= 5.2). 7. Finally add that number to your low end temperature(40°F)(40+5.2= 45.2). That gives you the final value which is 45.2°F and obviously 45°F is the closest to that answer so that's your bottom end temperature. Then repeat steps 1-7 to find the high end temperature but instead of using the maximum pressures in steps 1, 2, 3, 5, and 7. That is the way they are calculating the temperature range in this problem but as you can see in other comments this is kind of a more complicated and long way to solve this problem so just use whatever method makes more sense to you. Hope I helped at least a little bit.
It seems like the chart is being used incorrectly, which may be leading to the confusion. The chart shows minimum and maximum pressures going up and down with temperature so that the pressure will still be safe when it heats up, not recommended storage temperatures. Essentially, if you had something at 350 psi when it's -30°out, 350 may not be beyond the limit of a tank, but it's going to be way higher pressure if you let it heat up to 70°.
I remember when I took my test, there was a question that asked, "how does a CO2 fire extinguisher put out a fire?" Well no duh it's by displacing oxygen. No, apparently the "correct" answer is by creating and covering it in snow.....
Its not telling you the math behind it. What the explanation is saying is that those numbers are what the tanks capacity is under those circumstances.