Ever done this?

No, but I would have liked to have seen it

You could try something like this

but when I've come across a stubborn knockout I've normally been able to use channellocks by tilting them at an angle so one side of the jaws is on the back plate and the other on the edge of the knockout and then use a lever action to raise the edge of the knockout, but in your case the lever action could have broken the plastic fitting. The only time I have ever seen plastic fittings on sprinkler systems has been in residential applications.

Doug L

So this is how my day went....

Installing a Vista 32-FB in a county building to monitor hte sprinkler system (they have both wet and dry systems) Got flex to all the flow and tamper boxes except one and am working on the last... First step, knock out the knock out on the back of the box - careful of the 110 bell circuit already wired to one of the switches. Put my punch on the perimeter of the knock out and tap with my hammer...nothing... Second tap and the box breaks off, the bell starts ringing and air shoots out of whats left of the pipe (it was the low air alarm) I put my finger over the hole to keep whats left of the air pressure (now at just over 30 lbs) in the system until I can get the water shut off (lesson learned there - shut it off FIRST) The water valve is chained and no key in sight. Bell ringing right over my head but nobody seems to notice. For at least 5 minutes I am standing there under a ringing bell with my finger blocking the hole. I figure If the clapper releases I will then have water shooting out of a

1/4 inch hole with a lot more pressure than the air currently is. Finally someone notices me and I send them looking for the key to the chain holding the butterfly valve open. No key can be found and it takes several more minutes before bolt cutters can be found to cut the chain and shut off the water. The sprinkler guys show up later and replace the switch. The fella I spoke with said he has never seen one do that before, but theyt have recently started using plastic fittings to connect the tamper boxes to the pipes. (Plastic pipe, 3/4 od and 1/4 id) We tapped out both knockouts BEFORE mounting the box this time....

Question: Anyone got a better way of getting rid of those knockouts? I thought of a 7/8 hole saw next time but not sure how well that may work since they tend to get grabby and either twist off the box or slam my drill (and hand) into something delicate or energized.

I would rather not go through this again....

BTW, I later found the key in the spinkler repair parts box next to the wet risers on the other side of the building (which is the first place I told them to look)

One very embarrassing moment for me was a demo to a teacher in our school, who had just set off a false panic alarm . After the staff and students were calm and settled, I went to the room that sent the panic and talked to the teacher. Look, I told him, you have to hold the button down for two seconds (5802MN) to set off the alarm. Watch, I said. Push, push, push, SIRENS!!!!!!!!! What a way to find out the remote samples at two sec, and doesn't care what you do in between!

Rick

There's never an "easy" way, is there? Plastic pipe on a dry valve for a sprinkler system?? Not here! You'll see "blaze pipe" all over the place in most wet systems, but I've never seen it on a dry (which is mostly located in parkades and unheated out buildings) and *never* on any valve components (wet, deluge or dry). I do know the knockouts on some flow switches and other sprinkler devices can be a pain. I use an ice pick. I line it up with an edge of the knockout, not the centre. Once a bit of it is lifted away from the box, you can insert a screwdriver blade and twist the rest of it away. This doesn't put a great deal of pressure on the fittings.

Of course, taking care of the knock-outs *before* you mount the device is always the best solution, but often times I'm not there when they're installed. The sprinkler guys I work with all leave one of the knock-out holes punched out for later connection. Some even leave plastic plugs in place. Now *thats* thoughtful.

I once did not know that a water flow valve also was wired to trip the main power to a building. (This was something new at the time.) So I tested the water flow for the alarm and off goes the building power! Building manager was not pleased....

Then another time I forgot a direct wire fire system in a high-rise was also wired to bring all the elevators to the ground floor and *leave* them there until the direct wire was reset. The testing I was doing left all the elevators down. About 15 minutes after I started my testing, an angry building manager and several building maintenance guys stormed through the sub-basement door. Said; "Do you know you have all the elevators down on the first floor?" I said; "Oops, sorry!" - Then I quickly bypassed the elevator trip with a jumper and attempted to hide in the corner....

I've got two...

The first one was when I did a fire alarm test in a phone/data switching room for Sprint. There was a relay inside the panel to shut down the equipment in case of fire, and to prevent this, you pulled the relay off of it's base. But, no one told me that, and I managed to knock most of the people in my county off AOL with a little puff of canned smoke!

The second involved a dry system. I moved from Southeast Texas to Indiana. Back home, I'd never seen a dry system, so I barely knew what it was. So, when I turned the inspector's test valve, I was surprised that AIR seemed to be coming out instead of water.. Oops. Had to get teh sprinkler company out to drain and re-pressurize the lines, and I never opened a valve without asking again!