drafting

[HF&R_H28]

how do YOU prime the pump when drafting? (when out of water) lets say your drafting from a dry hydrant, or dump tank.

[Dalmatian90]

Um, not to be too sarcastic but, pull the primer knob.

Most (all?) fire apparatus pumps have a small, electric powered positive-displacement "Primer pump." Should prime 20' of suction and your pump itself in about 60 seconds from a 10' lift. That could take a lot longer (or not at all) if you have a small air leak or the primer just in plain old and worn out.

Some trucks setup to draft frequently will include dual electric primers.

My department's source pumper is setup with a hydraulic driven rotary vane pump normally found on septic tank trucks -- primes extremely fast, usually about 10 seconds. With a conventional electric as backup.

"Backfilling" the suction with tank water is a rare operation in my neck of the woods (not just my department).

[1835Wayne]

A lot of times I will backfill from the booster tank at the first sign that I'm having trouble pulling prime.If this gets it going for the moment,I hop down and take the hammer to the connections.

Also, our engine has them new fangled electric gates on all of our intakes. They make it easy to switch from the tank to draft, just close the tank to pump as youopen the steamer gate. Worked on the old hand valves too,depending on how the panel was set up.

[HF&R_H28]

yes, we tried the primer. the truck did not belong to my dept, but we have one exactly like it. we tried drafting from a dump tank, and couldnt get it primed. had no water in the booster tank, held the primer for a long time, never got it primed through it. finally i pulled a 2 1/2 and ran it to the tanker and filled the booster tank, and then once i pulled the tank to pump valve, it picked right up. our primer is much stronger than the one on that truck. but what i am asking is what is the best way to prime it when you have no water in the tank, and the primer wont pull it?

[hvfd507]

You may want to check to see if you have a tank valve leaking. With out water in the tank, you may be pulling air in the pump through the tank via leaking valve.
Also make sure there is plenty of oil going to the primer pump. The oil helps make an air tight fit in the primer pump. Good luck.

[JayTL]

You should be able to utilize the primer. If everything is tight, all valves are shut and you have used a rubber mallet to ensure that discharges are shut, except for the one you are using, you should be able to draft. Are you out of primer oil? Have you tried to drop prime in case your primer is not functioning?

[ENG6511]

Dal 90: You just couldn't resist--could you?

[HF&R_H28]

thx... im not really all that worried about it... truck doesnt belong to us. our truck just like it is in virginia getting a new tank, while it is there the primer, and everything else will get serviced.

[quintladder]

Fix the tank to pump valve and you should be all set

[kerfuffle]

Maybe a little off topic but something to think about......
Try priming without the pump spinning, This will prolong life of bearings and seals. In the Vol. dept I used to belong to the habit was to throw the pump in gear and then hop out of the cab. By the time you got around to getting the Hard suction hooked up and in the water 4 or 5 minutes had passed with the pump spinning dry, got to be hard on stuff! If you set up and pull prime before you engage the trans. the pump is still cool. Any pump worth its weight in scrap should hold a vacuum for the minute or 2 it takes to engage the trans. Besides the NFPA pump test requires it to hold for 10 min. I think. This will also give you a good idea about the condition of the equipment you're working with.

[Dalmatian90]

what i am asking is what is the best way to prime it when you have no water in the tank, and the primer wont pull it?

Pretty much the way you did. You either need a working primer, or water to backfill the suction.

[HF&R_H28]

Thats sorta what i was thinking. see.... im not as look as i dumb!!!

[Indiana]

Primer won't work? Stuff a discharge line in the end of your suction hose.