I've seen VIH head's cause problem's like that a couple of different time's. A lot of time's the pitot tube get's cut with a shovel and the head come's on, if the swingjoint is backfilled around that's not a big deal, but if it isn't then the the head flop's around, at 90 GPM, that can be a problem. But the worst was a toro 690 with a 1 1/2 inlet at 120 psi. The snap ring that hold's the head in the body was gone but the guy working on it didn't realize that. He turned the head on, without the lid, and there is a 1" x 1/2" internally threaded steel rod to hold that lid on. And the gut's of the head blew out and hit the guy in the mouth taking out three of his teeth, breaking his jaw and chipping his orbit. I never put my face over a head when turning it on, and i did this long before that happened, and this why.
Last edited by agrostis; 05-03-2013 at 01:31 PM.