Why The Injector Don’t Work

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4214 W. Chicago Street Rapid City, SD 57702

Have read the very fine letters on how the injector works. I am
sure that any old engine man has had times when the injector would
not take water. I will try to cover the causes and cure of those
troubles. First under the heading will not pick up water. Here are
probable causes. #l-steam pressure too low. Some injectors are
designed for higher pressures. #2-air leak in suction line. Many
times the pack nut on the inlet hand valve loosens up or packing is
worn or dried till it is no longer sealing. All injectors should be
equipped with a fine screen at inlet end of the feed pipe or hose,
and it may be clogged. If it is hard to get at and you need water
now, put a plug in the overflow and turn in some steam; it will
blow back through the feed line and screen. Then cool down the feed
line with cold water and try again. If that did not do it, take the
bottom plug out of the injector, the delivery tube should come
right with it. Look for obstructions. Is the feed water line hot?
If so, pour cold water over the injector and the feed or suction
line and try again. This trouble is usually caused by the boiler
check valve not seating right. This problem is rare but I have had
it happen. When using a hose to draw water to the injector, a
poorly made or old hose can have the lining of the hose separate
and when suction is applied it will collapse, shutting off all
water flow. This one is hard to find, try a different hose to find
out. If feed water is too hot it can’t be raised very far by
suction.

Now this problem is most common and has the most causes. The
injector will pick up water but just overflows. First take the
delivery tube out and check all the little holes in the side of it;
even a hair in a small injector in one of those holes will give
trouble. Hold it up to the light and look through the length of the
tube. Anything in there will stop the working of it. I once was
using a hose that was shedding flakes of rubber every now and then.
A piece of that would lodge in the tapered section of the delivery
tube. Another thing, if for some reason you try to take water from
a source at a level at or above the injector it won’t work
unless you pinch down the flow with the inlet hand valve. This
takes careful adjustment but can be done. A too long or restricted
pipe screwed into the overflow will cause trouble. Use a larger
size pipe if you want to deliver the overflow more than three feet.
Don’t panic if the injector doesn’t ‘take’; check
the possible causes at once then, if it won’t work and water is
getting low, reduce the fire or kill it with dirt shoveled on it.
Don’t ‘hammer’ on the injector. This won’t cure
anything and will damage the unit if continued. Remember you
can’t make a hot injector take hot water. Regarding hammering
the injector, I have seen one that was hammered in anger and
frustration until it was damaged beyond repair.

Once in a while the overflow check will get built up with
minerals from hard water. This will make it dribble out the
overflow. Take it out and clean it by laying a piece of very fine
sandpaper on a flat surface such as a piece of window glass and
move it back and forth carefully until the coating is removed.

An injector may work well except every now and then the overflow
will make a sound and burp a bit of water then take hold again.
This is caused by a tiny leak in the suction line somewhere. To
find, plug the overflow and the farthest joint from the injector on
the suction line, then turn on a bit of steam and you can see the
leak.

Above all, don’t fool with the injector till the water gets
too low. If you are on a load, shut it down, open the fire door to
slow the fire. Watch the gauge pressure, don’t let it pop off,
as what water is left will leave fast. If it continues to climb, a
few shovels of dirt scattered over the fire will subdue it. The
dirt can easily be raked down through the fire when you get water
in the boiler again. I hope what I have given about troubles will
help someone out of a problem sometime.

Remove your injector now and then, put it in a container and
completely cover it with vinegar. This works best if you remove the
delivery jet, let soak for several days, and rinse well with water.
This will remove most mineral buildup. For real bad buildup, use a
nine to one solution of water to muriatic acid. Caution: never pour
water into the acid, always pour the acid into water. Overnight
usually is long enough for this. Neutralize the acid with baking
soda.

Well, when all else fails, check to see if there is water in the
tank. Have fun steaming!

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