3000psi

[Woodwose]

So my new shoebox is a bigger hit than I expected with the local players. I have had people calling me wanting to come by and fill tanks. I guess I'm antisocial, so I ordered a scuba tank to be able to offer fills at the game.

I'm not super comfortable filling a 3kpsi tank with a compressor that will be perfectly happy to fill to 4.5k. Yes, I can shut it off early, but that is a fairly unreliable control.

If I wanted to CONVERT my shoebox to 3k psi, including a new burst disk so that it isn't a dual-pressure setup, and is safe, what would be the recommended way to do that? Move the switch? Adjust the vertical arm that hits the switch? New Spring?

If you (AGD) are looking for a 3k field tester, I'm interested.

Thanks,
'wose

[ShoeBox Tech]

If I wanted to CONVERT my shoebox to 3k psi, including a new burst disk so that it isn't a dual-pressure setup, and is safe, what would be the recommended way to do that? Move the switch? Adjust the vertical arm that hits the switch? New Spring?

Thanks,
'wose

Pleasae dont mess with the safety of your ShoeBox. There is no recommended way. We will not advise support or condone messing with the built in safety features.

DO NOT MOVE the switch. DO NOT attempt to adjust the vertical arm that hits the switch.
DO NOT MESS with the spring. The springs are custom made.

We will offer 3000psi ShoeBox's for sale in the near furture.

[Tunaman]

Once you figure out how long it takes to fill your tank just put the shoebox on a timer to shut it off.

[Woodwose]

Gotcha. No messing with the Shoebox. I will "put my hands in my pockets and walk away".

I like the timer idea Tuna. Thanks.

What about one of the electric pressure shutoff switches that have been mentioned before, plumbed in after the outlet of the compressor?

Like mcmaster-carr part 3427K83 which shuts off at 400-4700psi? The 5 amp rating should be plenty to wire in directly, and +-1.5% would be a very nice and tight shutoff range.

Thanks,
'wose

[brycelarson]

Gotcha. No messing with the Shoebox. I will "put my hands in my pockets and walk away".

I like the timer idea Tuna. Thanks.

What about one of the electric pressure shutoff switches that have been mentioned before, plumbed in after the outlet of the compressor?

Like mcmaster-carr part 3427K83 which shuts off at 400-4700psi? The 5 amp rating should be plenty to wire in directly, and +-1.5% would be a very nice and tight shutoff range.

Thanks,
'wose

that's pretty good.

[CrazyLittle]

I picked up one of those pressure switches, and as soon as I have it hooked up, I'll post a trip report.

[brycelarson]

I picked up one of those pressure switches, and as soon as I have it hooked up, I'll post a trip report.

didn't realize you got a shoebox. how much was the switch?

[Voltar1]

I recommend anyone wanting reduced pressure filling invest in a HP regulator.

Get one that will do 6,000psi inlet and 0 to 3,000 or even 5,000psi output.
That will keep the safety shutoff intact and seperate from the reduced pressure you need.
Set the reg at 3,000psi and fill to your hearts content.

The bottle will have 3,000psi in it and the reg supply will go up to the shutoff and stop.
I am going to do this and I beleive there is an additional gain. The time that the spring arm slaps at the switch will be very short as it will only build pressure into a small volume upstream of the regulator.

'Tis 'ow 'm gonna do it

Walter....

[MikeB]

I recommend anyone wanting reduced pressure filling invest in a HP regulator.

Get one that will do 6,000psi inlet and 0 to 3,000 or even 5,000psi output.
That will keep the safety shutoff intact and seperate from the reduced pressure you need.
Set the reg at 3,000psi and fill to your hearts content.

The bottle will have 3,000psi in it and the reg supply will go up to the shutoff and stop.
I am going to do this and I beleive there is an additional gain. The time that the spring arm slaps at the switch will be very short as it will only build pressure into a small volume upstream of the regulator.

'Tis 'ow 'm gonna do it

Walter....

Most regulators I have seen bleed or bypass any air above their set pressure. So I think the Shoebox would never reach shut off pressure and run continuously. The tank would have set pressure though.

[Voltar1]

Most regulators I have seen bleed or bypass any air above their set pressure. So I think the Shoebox would never reach shut off pressure and run continuously. The tank would have set pressure though.

Never had occasion to see or use any such regulator as you describe. The regs for this app will not vent or bypass and will 'shutoff' when the downstream pressure is reached. As there is no longer air leaving the fill system the Shoebox will build to the mechanical shutoff setpoint.

So I have no idea where you have dealt with such regulators but I have yet to see one.

Walter....

[Voltar1]

In my fittings assortment I found a neat little device that will work for teh Shoebox to control output pressure.

It is made by Chemiquip and model is PLV 255 available with a 1,000 to 3,000psi spring.
1/4" npt threads and easily adjustable.

Got mine hooked up and the compressor makes air up to 3,000psi at which time the PLV (pressure limiting valve) closes off the inlet. The compressor happily continues to run up to the 4500psi that the cutout is adjusted for. What is coolest to me is the arm is not slapping at the on/off switch until the last minute of running. Pressure ramps up quickly as the volume is small.

I like it and may get another set for 4500 if they are available.

Walter....

oh BTW will see what they are worth

[Voltar1]

Been using the Pressure Limiting Valve fo a few fills now. I reccommend this as an accesory for all airgunners that have a reduced pressure fill requirement. It is now my opinion that Tom setup the compressors for 4500 and be done with that.

The Limiter is $88usd in brass and IMO a great deal.

Walter....