DIY pressure pot.. what size pipes?

[Bahja]

Hi, I'm looking into DIY-ing a pressure pot for sand blasting.

I have a compressor capable of 160 CFM.

I have an empty lpg gas cylinder.

Cfm charts suggest piping should be 1.5" to take advantage of the 160CFM.

But does this mean all the pipework and fittings on the blast pot itself should be sized to 1.5" ?

I may not need this hose size for the actual sand blast gun most of the time as it would probably be unwieldy, however I want the pressure pot itself to be capable of the full compressor output when required (and just swap the sand blast gun hose when needed)

If so does this mean the output port on the pot (where the abrasive is forced out into the metering valve) needs to be replaced for a 1.5" ?

Any advice appreciated

Thanks

 

[Dcal]

Hi and welcome to the forum.

What are you blasting?
You can blast at the full rating of the compressor but you will need a big nozzle, big pipes, lots of grit and you had better be doing structural steel or the like because you will destroy anything lightweight.

 

[frank horton]

I used a road compressor for sandblasting things like old car and truck chassis plus tractor parts......
it had a 100m big black hose about ur size......this enabled me to keep the noisy thing a long way away......
back to ur questin......
I connected this pipe to a large comprssor tank 150ltr and used its regulator to keep things under control.......
the blasting unit was one of those cheapo efforts from the bay of thieves........
all in all this helped by never straining the norm compressors, could run till the pot was empty.....for me two pots of sand equalled a brew.....hahaha...
always used a water trap, a large'ish after market add on.......
usually had enough after 4hours doing blasting tho.......
hope this helps

 

[Bahja]

Thanks for your replies.

It will need to be capable of light work in a cabinet but potentially also more heavier stuff which we will do outside like steels etc.

It's not the blast hose itself I guess I can change that as required, it's the other pipework from say inlet valve to metering valve and the port where the metering valve is connected... what sizes should they be. If I've got 1.5" incoming then 1.5" branched to pot inlet and 1.5" to metering valve, could that be detrimental as I'm feeding 2x1.5" with a single 1.5"? Maybe its a trivial point!!

I found some dimensions after posting from some blast pot manufacturers so may just use what they have done.

 

[brightspark]

I run an 90cfm comp and the pot uses a 6.0mm blast jet the hoses from comp are 3/4 bore which is well adequate even if your running a bigger jet on pot . you have stated your comp size but not which pot size u intend to use if u have a 160 comp at full whack do u intend shotblasting buildings tanks and wagon chassis cos that's what u will get I hardly think u are going to put one together big enough with a gas bottle .il flog u a large bore grit valve for 40 quid if u are building one

 

[Dcal]

Unless he is thinking of using a bulk gas tank.

Another point worth considering is if you are using a small nozzle it is better to have appropriately sized kit down stream.
I would make two, one for small stuff (with a smaller tank, pipework and metering valve) and a big one for when you need to get the big guns out.
A metering valve that can feed a 6 or 10mm nozzle might struggle with a 3mm.
Also pulling all the kit out for a small job would get old very quickly.

 

[Bahja]

@brightspark
Food for thought, a 6mm nozzle would probably be plenty enough. Thanks for the offer may take it up I've got my eyes on a few options at the moment.

@Dcal
I could do 2 if needs be. Will the bigger inch and a half valves not meter down as finely?

Im weary of limiting ourselves in the future buying undersized valves only to find we don't have enough capability when we need it.

 

[brightspark]

mines a 10mm hose on the small pot and a 15mm blast hose using the 6.0mm jet that is the correct size hose for both

 

[brightspark]

to be honest anything larger than car wheels or bigish surfaces it needs to be bigger than the 6.0mm jet at 90cfm unless your in no rush . if your doing it as a business times money and u need the bigger gear and preferably a big shed to do it in