A few days ago, someone brought me a live fragmentation grenade - in the form of a vintage Crosman Mark I, with a regulated HPA tank fastened to a hangy tank adapter.
Why do I refer to it as a "fragmentation grenade"? Because that pot metal Mark I frame, was charged to 3000 PSI !!
These guns were simply NOT designed to withstand pressures in that range, and that pot-metal frame could have potentially exploded, causing serious injury.
The HPA tank could not be unscrewed, nor was the gun capable of firing.
Upon realizing what I had on my workbench. I immediately wapped the entire gun in heavy blankets to at least reduce the danger to some degree, to myself and the gun's owner, until the pressure could be bled down. The reg side burst disc was cracked open enough for the pressure to bleed off.
Needless to say, I had a few unpleasant words for the owner while the tank was bleeding down. In his defence, he explained to me that he had purchased the tank from a member of one of the Canadian forums, and had been told by the seller that the regulator was set at 750 PSI. He trusted the word of the seller, and upon receiving the tank, just screwed it onto his Mark I - big mistake. When he tried to contact the seller to ask for advice on what to do, since he could neither remove the tank now, nor fire the gun, he received no response at all.
With the background story more clearly understood, and after the tank had bled down to zero, I removed the 1.8K burst disc assembly to try to figure out why the burst disc hadn't blown, as it obviously should have. What I found was infuriating - someone had plugged the vent hole of the burst disc assembly with a set-screw !! Why would anyone endanger the safety of another person for the price of a lousy three or four dollar burst disc? Worse yet, why would they tell someone that the tank is regulated at 750 PSI, when in fact the regulator was essentially non-functioning and outputting 3000 PSI?? As is so typical, "Mr Modder" screws up what he is working on, and then rather than eat the loss for his own incompetence, he sells it to some unsuspecting fellow airgunner who takes the loss. Disgusting.
I have advised the owner to replace the frame of this Mark I, and destroy this over-pressurized one, as IMO, it is no longer safe to use, even at CO2 pressures.
The owner of this gun was extremely lucky that no one was injured as a result of someone else's neglegence and dishonesty.
Please, for your own safety, if buying a used regulated HPA tank, test the output pressure before attaching it to your favourite airgun.
Why do I refer to it as a "fragmentation grenade"? Because that pot metal Mark I frame, was charged to 3000 PSI !!
These guns were simply NOT designed to withstand pressures in that range, and that pot-metal frame could have potentially exploded, causing serious injury.
The HPA tank could not be unscrewed, nor was the gun capable of firing.
Upon realizing what I had on my workbench. I immediately wapped the entire gun in heavy blankets to at least reduce the danger to some degree, to myself and the gun's owner, until the pressure could be bled down. The reg side burst disc was cracked open enough for the pressure to bleed off.
Needless to say, I had a few unpleasant words for the owner while the tank was bleeding down. In his defence, he explained to me that he had purchased the tank from a member of one of the Canadian forums, and had been told by the seller that the regulator was set at 750 PSI. He trusted the word of the seller, and upon receiving the tank, just screwed it onto his Mark I - big mistake. When he tried to contact the seller to ask for advice on what to do, since he could neither remove the tank now, nor fire the gun, he received no response at all.
With the background story more clearly understood, and after the tank had bled down to zero, I removed the 1.8K burst disc assembly to try to figure out why the burst disc hadn't blown, as it obviously should have. What I found was infuriating - someone had plugged the vent hole of the burst disc assembly with a set-screw !! Why would anyone endanger the safety of another person for the price of a lousy three or four dollar burst disc? Worse yet, why would they tell someone that the tank is regulated at 750 PSI, when in fact the regulator was essentially non-functioning and outputting 3000 PSI?? As is so typical, "Mr Modder" screws up what he is working on, and then rather than eat the loss for his own incompetence, he sells it to some unsuspecting fellow airgunner who takes the loss. Disgusting.
I have advised the owner to replace the frame of this Mark I, and destroy this over-pressurized one, as IMO, it is no longer safe to use, even at CO2 pressures.
The owner of this gun was extremely lucky that no one was injured as a result of someone else's neglegence and dishonesty.
Please, for your own safety, if buying a used regulated HPA tank, test the output pressure before attaching it to your favourite airgun.
