Injector Questions

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doublereefed
Posts: 210
Joined: Wed Jan 30, 2008 7:24 am
Location: Manhattan Beach, CA

Injector Questions

Post by doublereefed »

I'm wondering about pipework for injectors. I have 2 locos with Superscale injectors, both piped with 5/16 lines in and out (I think... not near the locos this weekend while I ponder this question). Both setups work fabulously. My question is this: what is the relationship of the water supply and delivery lines, and then the check valve? For instance could you supply at 5/16, but deliver to the check valve at 3/16, or 5/32? Do injectors handle this?

Related to this, I see British type injectors rated with numbers (No 2, 3, 4, 5, 6)... but in 7 1/2" and 7 1/4" gauge equipment (all scales) there are no such designations, even with Superscales line of different injectors, and with Eccentric Engineerings new offers.

Thanks,

-Richard
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Builder01
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Re: Injector Questions

Post by Builder01 »

The number designation on the injectors sold in England is in reference to delivery capacity. Here's a link to a website page of English injectors: http://www.livesteammodels.co.uk/shop/i ... ath=49_149

The capacity is given in pints per minute for each size. They are sold in both horizontal and vertical versions of each size. I have a #4 injector on my 1" scale loco. My boiler barrel is 5" in diameter by 19" long. The injector feeds it well, and including shipping price, it is a bit more economical than the injectors sold in the U.S.

David
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Fred_V
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Re: Injector Questions

Post by Fred_V »

i'm don't know for sure but I would thing a 3/16" delivery line would be too small. I once worked on an engine with an LS Chicago injector that would not work; just blew water/steam out the overflow. It had a 5/16" delivery tube but it turned out to have only a 3/16" ID. heavy wall brass tube. I changed it to 5/16" copper tube and the injector started working.
Fred V
Pensacola, Fl.
doublereefed
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Location: Manhattan Beach, CA

Re: Injector Questions

Post by doublereefed »

Thanks for the comments. It would make sense that the injector and check valves be matched/compatible in terms of pathway diameters.
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Bill Shields
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Re: Injector Questions

Post by Bill Shields »

general guide: the feed / output lines from an injector can never be too big....
Too many things going on to bother listing them.
Soot n' Cinders
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Re: Injector Questions

Post by Soot n' Cinders »

Also, too small of a water feed line will also mess up an injector. I had too small of a filter on my injectors and while they would put water in the boiler, probably 20% went on the ground. Granted mine are up in the lifting position, but switching to a larger filter corrected the problems and the injectors ran with a dry overflow afterwards
-Tristan

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