Sprinkler valve pressures

[Nereth]

Ive got my hands on 2 2400S50H valves, from irritrol. Curiously, they seem to be exact copies of orbit watermaster 1 inchers, except grey and with a marginally different shaped female thread on either end.

So the question is, how high can I safely pump these things? theyve been modded to pneumatic operation through a 10mm (3/8") vent, so actuation isnt a problem, and also, everything else on the gun is rated between 260 and 500 PSI, so nothing else will fail. These valves are setting the upper limit to my gun.

On the website, it said theyre rated for 150 PSI, however i heard somewhere else that for running gas through em, you should take some 15-20% off that rating to stay safe. At the moment im taking the upper limit as 125 PSI. What have you guys pumped your valves to?

Oh, and ive got a box of old unlabeled valves outside. From the outside , they look to have the same construction as 1" rainbird inlines. Except they dont have a bleedscrew in the middle. I live in Australia so i think were getting American valves imported and relabeled. To be honest they might not be rainbirds, i havent taken them apart in ages. If they are, Will they be better to use in place of the '2400S50H' valves?

[boilingleadbath]

Generaly, pressure ratings for pipe have a saftey factor of about 4.
You shouldn't have any problems running them at 150 psi, but generaly keep clear of the 'top' of the valve incase the lid pops off - I suspect that's the most likely failure.