Author Topic: 5k Burst Disc Popped  (Read 373 times)

steveoh

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5k Burst Disc Popped
« on: September 02, 2018, 06:29:12 PM »
Operator malfunction I think. Popped the 5k burst disc in the Small Air Venturi / Ninja tank. Crap. I see another SCBA tank in my future and perhaps a real compressor.  Don’t think this Yong Heng is long for life, with me trying to stuff in 4500psi of air in a big tank. Cooling inadequate even running with ice in the water.

Bah!


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Steelhead

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Re: 5k Burst Disc Popped
« Reply #1 on: September 02, 2018, 07:46:06 PM »
Bummer. I've come to find that it's accepted in the airgun world that things are going to fail. I credit this to the fact that PCP is relatively new. Other hobbies and shooting sports go back decades and decades but PCP's and the related equipment is still being developed. Some things work, some things don't. The technology race is on and the equipment hasn't been really put through the test of time. There's actually very little that's tried and true, and that's especially true of big bore guns. As you well know even high end quality equipment has it's quirks.

It may or may not have been worth a shot, but enough people use a YH compressor to take a gamble. For comparison's sake if you were shooting a .22 FX Crown you might get 50 shots or more (just a guess, I don't really know) on a 3000 psi gun fill. That means that compressor isn't running very often to fill a tank and you don't need to put that load on it for a 4000psi fill. You can shoot forever on a 3500 fill. But as you know the big bores (especially yours...holy $#!t)  really chew through it. I'll give you one thing, you're putting that compressor through it's paces. I have a feeling that you're seeing the breaking point. If it makes you feel better even if it through a rod today you'd still have saved the $'s/time from having to pay for fills previously to offset the cost. The logistics and money to pay to fill for every shoot is brutal.

Now that you've had a taste, you can't go back to doing offsite fills. Start thinking about a suitable replacement before the yong heng decides to take a permanent vacation. I know Alan loves his Omega, and I have 11 hours or so on my Air Venturi and have had zero problems (fighting off a serious jinx paranoia right now)  My guess is that no matter what brand/design you go with you'd at least be looking at $1500.00. I know you'd mentioned gas power before; that's way out of my price league (bowing reverently)

Just got in from Monterey. Looking forward to the shoot in the morning.
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steveoh

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Re: 5k Burst Disc Popped
« Reply #2 on: September 02, 2018, 08:12:03 PM »
Yep, things are gonna break. Kinda like my 97 Dodge surrounding a Cummins. 500,000 + engine attached to a 100,000 mile truck. Stuff breaks all the flipping time. At 240,000 miles engine is just broken in.

Got the big tank filled, and all the rifles. Just did my second oil change on the Yong Heng and it is pretty dark at maybe 40 minutes of run time. Also changed out the Tampon filter and it was wet. Not happy about that either. So will need to add a secondary filter/dryer.

Going to half to start freezing gallons of water to keep this thing cool. It really needs a more powerful fan to cool the crankcase. Speaking of crankcase it needs fins or a deeper sump. Too hot.

One of those portable compressors would be cool for shoots.

I was thinking about these dump guns and I’m starting to think less spring and more efficiency might be a reasonable goal. Back to less air pressure and lighter bullets.

The Sam Yang 909s consumed a lot less air than the DAQs. I fill it only to 3k, and I’m getting 3/4 shots. DAQs I’ve been going higher and refilling every shot. I sure do like the wallop though.

Bringing Marauder because it sips air as I fill it to 2500 psi.

Can’t wait to head your way tomorrow. Trying to convince Henry to come. But the Xbox calls. :(
  • Benicia, California
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Frank in Fairfield

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Re: 5k Burst Disc Popped
« Reply #3 on: September 03, 2018, 06:28:22 AM »
“the fact that PCP is relatively new”

Kevin,
PCP air arms are not really that new.
Lewis & Clark had one on their trip across America 1804-06.
I have a photo.
BTW...It was their “bear gun”.

Stay safe
"Good judgement comes from experience, and a lot of that comes from bad judgement."

Steelhead

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Re: 5k Burst Disc Popped
« Reply #4 on: September 03, 2018, 08:57:25 PM »
Technically, yes. But I don't remember too many guys running around with air tanks and fill nipples in the 70's and 80's. Pumps and cocking levers. My point is that a Remington 700 today ain't much different than one from 50 years ago. But there's a big difference between an 'old' PCP like a Discovery and a new air gun. The 'arms race' is in full force to make more power, longer distances, and more shots. That coupled with the internet makes it hard to sift through the b.s. of what's real, what's not, and what falls in between.
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Alan

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Re: 5k Burst Disc Popped
« Reply #5 on: September 04, 2018, 04:48:37 AM »
I've always wanted better pellets, but looking back on that issue, I think the most important part is a better airgun! I am convinced that I have that now (WAR Cobra). And my recent looking into terminal ballistics has me convinced the the JSB Kings (25.39 grains) are about the best killers out to 200 yards. State-of-the-art? I can't imagine what would be better than I have now?
  • Roswell, New Mexico
Alan

I have an Omega compressor. If you're a fellow Guild member, and you pass through Roswell, NM, I'll fill your portable tank as a courtesy.

sixshootertexan

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Re: 5k Burst Disc Popped
« Reply #6 on: September 05, 2018, 07:27:50 AM »
The 5K disk is known to fail with the shoebox type compressors. It does not like the small pulses of pressure repeated thousands of times from a shoebox. Why it's failing with the Yong Heng I don't know. I replaced mine with a 7.5K and never looked back.  I really don't know what a 5K disk is going to protect. It's larger than the fill pressure of the tank itself. If you have a full tank at 4500psi as soon as you crack the valve to fill something you are below 4500.
I no longer have a pissed off wife getting woke up at 3am from a weakened 5K disk letting go.
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rsterne

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Re: 5k Burst Disc Popped
« Reply #7 on: September 05, 2018, 09:14:58 AM »
I'm not familiar with the compressor mentioned, but most compressors (eg. ShoeBox) have a burst disc on the output to protect both the compressor and the tank you are filling, should it not turn off.... The 3000 psi Shoebox has a 5K burst disc and the 4500 psi unit has a 7.5K burst disc, exactly what the Hydrotest pressures on the tanks they are intended to fill are....

Using a 7.5K burst disc to protect a 4500 psi tank from being overfilled by the compressor is a wise thing to do.... It they come equipped with a 5K disc and you replace it with a 7.5K, that may allow some part of the compressor to fail before the burst disc.... It certainly shouldn't, if all parts are designed with a 3.5:1 safety margin, that would allow it to blow a 7.5K disc and still have a 2:1 safety margin in place....

but we don't really know what safety margin is designed into anything we buy, do we?....  ::)

Yes, I would expect a 5K burst disc to eventually fail with any compressor with a 4500 psi output, because the output pressure may fluctuate with the motion of the piston, particularly if the valve on the tank being filled is not fully opened (ie just cracked)…. Those pressure fluctuations flex the disc and fatigue the metal, causing the failure by reducing the tensile strength of the metal in the disc....

Bob
« Last Edit: September 05, 2018, 09:18:11 AM by rsterne »
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sixshootertexan

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Re: 5k Burst Disc Popped
« Reply #8 on: September 05, 2018, 09:36:42 AM »
The 5k is on the output side of the regulator. A 7.5K is on the tank side to protect from overfill of the tank.
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rsterne

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Re: 5k Burst Disc Popped
« Reply #9 on: September 05, 2018, 11:31:37 AM »
Sorry, I completely misunderstood.... I thought the burst disc was on the output side of the compressor.... I don't understand how the output side burst disc on a regulator gets flexed by compressor pulses.... because once the regulator closes at it's setpoint pressure, it is isolated from the input side....

Bob
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