thewishman
Member
If I have a pot that is labeled by the manufacturer to 45 psi and I want to cast at a higher pressure, 50 or 60psi, what should I do?
If I have a car and the tachometer has a red zone of 8,000 - what will happen when I run it to 8,500? Will the engine fail the first time I do it? What about the third time? How about the tenth time? Will there come a time that your engine will fail?
Exceeding a pressure pot's MAX RATING may work the first time, and the third time. After I have a few casts over the rating, I have proven that I can be successful at that higher than max pressure.
If a car's engine gets blown it will stop running. If your pressure pot blows, you could be seriously hurt.
Cars have rev limiters, and yeah, there is a pressure relief valve on the pot. It probably costs the manufacturer a dollar or two. How do you know what that cheap valve is set at? What if it doesn't work?
When I decide to push my car past the 8,000 red line, all the way to 10,000 (25%) it must be okay, because the rev limiter didn't shut it down, and my car still runs. I'll only do that once a week, so that should be okay, if I succeeded the last few times, it obviously is not a problem.
If you can put 60 psi into a tank rated for 45, you are exceeding the rating by 25%. Obviously your relief valve doesn't work. Who will be responsible for damage to your shop, or injuries caused by tank failure?
Please think, is it worth the chance of being hurt to run my pot pressure too high?
You can cast PR with no pressure. 20 psi is effective, I use 50 - 60 with complicated blanks that could trap air bubbles. My pot is rated for 85 psi.
Would you be comfortable having your children or grandchildren in the shop while you are casting at a too-high pressure? Your children or grandchildren love you, too - why would you take such a chance with your own safety?
If I have a car and the tachometer has a red zone of 8,000 - what will happen when I run it to 8,500? Will the engine fail the first time I do it? What about the third time? How about the tenth time? Will there come a time that your engine will fail?
Exceeding a pressure pot's MAX RATING may work the first time, and the third time. After I have a few casts over the rating, I have proven that I can be successful at that higher than max pressure.
If a car's engine gets blown it will stop running. If your pressure pot blows, you could be seriously hurt.
Cars have rev limiters, and yeah, there is a pressure relief valve on the pot. It probably costs the manufacturer a dollar or two. How do you know what that cheap valve is set at? What if it doesn't work?
When I decide to push my car past the 8,000 red line, all the way to 10,000 (25%) it must be okay, because the rev limiter didn't shut it down, and my car still runs. I'll only do that once a week, so that should be okay, if I succeeded the last few times, it obviously is not a problem.
If you can put 60 psi into a tank rated for 45, you are exceeding the rating by 25%. Obviously your relief valve doesn't work. Who will be responsible for damage to your shop, or injuries caused by tank failure?
Please think, is it worth the chance of being hurt to run my pot pressure too high?
You can cast PR with no pressure. 20 psi is effective, I use 50 - 60 with complicated blanks that could trap air bubbles. My pot is rated for 85 psi.
Would you be comfortable having your children or grandchildren in the shop while you are casting at a too-high pressure? Your children or grandchildren love you, too - why would you take such a chance with your own safety?
