iIs that a pressure relief valve off of a hot water tank or a boiler.

Low pressure releif. 15lbs. It didn't work the best untill i made the mods you see in the pic. It leaked water out the stem.


http://www.grainger.com/Grainger/items/1CKX6

relife valve
 

what mods did you do to the relief valve other than the barb in the outlet?did you dump through the transome?anyway you can dump back into the system other than dumping overboard?

I dumped over board through a thru hull fittiing. I used
1" hose. I cut about 3/8 off the spring. Shorten the stem by 1/4 " and made the nylon piece to screw in the top to hold the valve in place. Put the valve back together using a sealer. Hope this helps. Like I said before this works great. 15 lbs at 3800 and about 20 lbs @WOT

Check this thread out at Boat Freaks.com

http://forums.boatfreaks.org/showthr...ressure&page=2

Better pic of the nylon piece.
Click on it to make larger.

relief valve
 

pretty coolstuff noise pollution.what kind of pressure were you seeing to make you go w/a relief valve.i changed my drive last year on my fountain.it has a multi-pick-up on the water inlet.my boat guy said all the new bravo1 come that way.since then my pressure is higher,wot about 30-35.boat guy said mercury said that is ok.i have heard diffrent stories from diffrent people.so i am wondering.

I was seeing up around 45 lbs. Your really pushing the limit with that pressure. Merc's $$$$ cheap piece of plastic is set around 22lbs.

I have the same style drive, LWP & side pick ups, I tapped all 4 front holes & plugged them off, the side pick ups will provide sufficient water supply

water pressure
 

did that cure your high pressure?