SpudFiles

Hi,

Why do both the Supah and Mauler valves have pressure limits? Is it to do with how they're put together (the bolts) or is that the rating of the components (T/reducers etc)?

Cheers,

Michael

Methinks it's only as good as the weakest component, which is probably the pressure rating on the tee.

it wouldnt make much sence tto fill plastic with 300 psi now would it? flying salt is right.



edit- the more pressure you put in it, the faster the piston comes back.

I'm just wondering why they are given ratings when no other components are.....That's why I think it has more to do with the construction of them then the materials....

Michael

Gepard wrote:I'm just wondering why they are given ratings when no other components are.....That's why I think it has more to do with the construction of them then the materials....

Piston valves were never on the minds of any engineer when they designed the pipe.
The valve exerts huge compressive forces on the sealing face (of the order of thousands of newtons), which was never intended. Pipe was designed to take tension forces, rather than compressive ones, so there are risks involved.

The other problem would lie in the piston coming back too violently at higher pressures, and potentially endangering the rear of the valves.

Too much pressure, and either problem could arise, potentially fatally.

I'm not sure I'd agree that they were designed to take purely tension forces....

Assuming longitudinal tension:
The only conditions I'd imagine where they'd be present is in an unsupported section where it sags and then you have both tension and compression on opposite sides of the pipe.....

Assuming radial tension:
You have the weight of the soil or surrounding material that exerts a compressive force on the pipe which yes may be nothing compared to the 10-16Bar internal pressure but at some point they have to be turned off....

But the extreme forces would certainly make sense....Anyone care to share some light of where the 125psi limit comes from? Seems too rounded to be a result from trail and error....

Michael

Thats probably because it is not from trial and error, but rather, as you stated, is a nice round number. What is the maximum pressure most people take their cannons (sch. 40 PVC mind you)? 120-125 PSI. Therefore, because it is a nice, round, and common pressure, both Maulers and Supahs are rated at 125 PSI.

I'm still not about to take one over 125, however, in case I am completely off base with this and extensive testing has been performed.

also the maker of the valve doesnt want to be sued when it gets taken to 150 psi. its safe to use at what its rated at and nothing more.

And becides, the mauler or supuh has to be acuated with a sprinkler valve ussually, thairfore the highest pressure is 120psi. I know you could acuate it with a ball valve too but why would you want to?

you can actuate it with a smaller piston valve!! like a 3/4 QEV for proper openign times!

Praetorian91, I don't know - purely 'cos if you make something you want to make it seem like the best out there. And so dumbing down the spec doesn't do you any favours. Though I must admit the fact that people run at 125psi I guess it a bit too much of a coinsidence....Is Gort still a member here? I'd like to hear it direct from him.....

Hi, I agree that something is safe to use at what it is rated at, I've never denied that - but I want to know where that rating comes from....

Turbohacker, surely you've answered that question yourself? You want to use a BV so then you can go with higher pressures.

Do I take it then Sch40 is rated at 125psi then? (I'm UK so I'm not familar with it)

Michael

Because they don't want you to hook it up to a c02 tank and fill it with as much pressure as you can and have it explode in your face. Thats why. If you put too much air pressure in it it will burst. As with steel and any other materials.

it depends on the pipe size. sch40 2.5'' is rated at 250 psi i think, but because there is a piston slamming into it the ratting is less.

MisterSteve124, I realise that it has to have a rating but as I said before I'm trying to work out where it comes from.....

I've email Gort, so I'll post what he replies.....

Michael

Lets get this one cleared up! Straight from the Gort's mouth!

The real question may be, however, which is more powerful? Both have two inch porting.

Argue away.