The Cache Pipe
One of the more exasperating chores in the pool business is priming a pump.
A simple reason is the ' pool professional ' who installed the pump didn't understand the importance of the cache pipe. The cache pipe is that vertical section of plumbing that exits the top of the pump.
To be efficient, the cache pipe must hold at least 2lbs of water to press out air caught in the vacuum- side plumbing. Using 2" pipe, that's about 9" and 1.5" pipe should be at least 2' long. (photo right) Only 6" of pipe added to this cache greatly eased priming.
To prime a pump, you fill the strainer basket (under the clear cover) with water. This water is your primer cache. Simply over-filling the strainer basket only sends a flood of water back to the pool through the suction- side plumbing on the front of the pump.
But you can maximize this cache (as much as the cache pipe will hold) by running a garden hose in the strainer basket and turning on the pump. When you turn the pump 'on', water is thrown up into the cache pipe and the spinning impeller holds it there in a vibrating mass.
Resecure the strainer basket lid and turn 'off' the hose. The strainer basket will look empty but that extra water in the up- right pipe adds weight to the primer cache. An impeller can't move enough air to blow out a birthday candle but this water mass is held in high, excited suspension, exerting an up and down pressure like a molecular hand pump.
Air bubbles up through this vertical cache because air is lighter than water. Nature abhors a vacuum so as air evacuates through the cache, pool water is towed along behind it. As soon as water finds its way to the strainer basket, the impeller picks it up and.....
we pumpin' !
Two more things you can do to help a pump prime:
And, one thing you cannot do:
Learn something you didn't know before ? Pool School PRO has hundreds more lessons and tips for pool owners and pros, alike !
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