Penberthy Injector question
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Penberthy Injector question
Hello All,
I have thrown this question out in several forums hopefully to get feedback on whether I can relocate this 3/8” Penberthy injector to a higher location on my Ottaway. If I re mount the injector at mid boiler height, I can run a straight injection pipe forward to the check valve, with no bends or restrictions in the output steam-water flow.
However, many people I’ve spoken with say these injectors can not lift water from the bottom of the tender. So raising the injector to mid boiler wouldn’t work.
Penberthy used to publish a table showing how high theninjector could lift water, at various steam pressures. however, they defined whether they meant suctioning water out of the tender to height, or if the lifting distances pertained to pushing water out of the injector to the boiler. Very confusing.
Anybody know the real answer??
I need to add a new injection line to the boiler, so need to make a decision whether or not to relocate the injector to a more secure, and higher location. (Enabling a better run for the output line)
Thanks
Glenn
I have thrown this question out in several forums hopefully to get feedback on whether I can relocate this 3/8” Penberthy injector to a higher location on my Ottaway. If I re mount the injector at mid boiler height, I can run a straight injection pipe forward to the check valve, with no bends or restrictions in the output steam-water flow.
However, many people I’ve spoken with say these injectors can not lift water from the bottom of the tender. So raising the injector to mid boiler wouldn’t work.
Penberthy used to publish a table showing how high theninjector could lift water, at various steam pressures. however, they defined whether they meant suctioning water out of the tender to height, or if the lifting distances pertained to pushing water out of the injector to the boiler. Very confusing.
Anybody know the real answer??
I need to add a new injection line to the boiler, so need to make a decision whether or not to relocate the injector to a more secure, and higher location. (Enabling a better run for the output line)
Thanks
Glenn
Moderator - Grand Scale Forum
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
- AnthonyDuarte
- Posts: 491
- Joined: Tue Jan 19, 2010 10:46 am
- Location: Orange, CA
- Contact:
Re: Penberthy Injector question
Hi Glenn,
The Penberthy injectors should be able to lift water when installed above the tender.
If you want to be absolutely sure, you can test its lifting ability on air. With the delivery outlet blocked (as it would be in operation), run air through the injector and see if there's a notable vacuum on the water suction line. If it's a lifting injector the vacuum will be significant. You can even try this with clear tubing and try sucking water. You'll see it make its way to the injector, but obviously once it gets there nothing will happen since injectors don't work on air.
Here is a youtube video of one in operation well above the water source. The injector is turned on around 2:25
Anthony
The Penberthy injectors should be able to lift water when installed above the tender.
If you want to be absolutely sure, you can test its lifting ability on air. With the delivery outlet blocked (as it would be in operation), run air through the injector and see if there's a notable vacuum on the water suction line. If it's a lifting injector the vacuum will be significant. You can even try this with clear tubing and try sucking water. You'll see it make its way to the injector, but obviously once it gets there nothing will happen since injectors don't work on air.
Here is a youtube video of one in operation well above the water source. The injector is turned on around 2:25
Anthony
Re: Penberthy Injector question
I had both a 3/8 and a 1/2 inch Penberthy on my 1/2 scale traction engine and neither had any trouble lifting 2 feet.
Having minimal resistance in the discharge is also important so I think what you loose on one hand you will make up for on the other.
Having minimal resistance in the discharge is also important so I think what you loose on one hand you will make up for on the other.
Re: Penberthy Injector question
No problem with a 2' lift. I have used 1/4 and 3/8 in.
John B.
John B.
Re: Penberthy Injector question
My 14” gauge Wagner was built in 1928 with 2 Penberthy 3/8 injectors in the cab about a foot higher then the boiler inlet. The lift from the tender bottom is about 3 feet plus. I leave the water values open and only open the steam values when needed. The injectors have always immediately picked up.
Re: Penberthy Injector question
I think a Penberthy will lift about 12 feet. The output is not as fussy as miniature units either.
Fred V
Pensacola, Fl.
Pensacola, Fl.
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- Joined: Wed Jun 27, 2012 5:24 pm
- Location: Marietta, Georgia
Re: Penberthy Injector question
This should work just fine. On tip for leaving the water valves open, drill a small hole or some other intentional leak in the overflow pipe above the tender level as well. Otherwise the water will siphon through the injector and out the overflow, eventually emptying the contents of you tender onto the right of wayCraig wrote: ↑Thu Dec 13, 2018 10:35 pm My 14” gauge Wagner was built in 1928 with 2 Penberthy 3/8 injectors in the cab about a foot higher then the boiler inlet. The lift from the tender bottom is about 3 feet plus. I leave the water values open and only open the steam values when needed. The injectors have always immediately picked up.
-Tristan
Projects
-2.5" scale Class A 20 Ton Shay
Steam Siphon: https://www.shapeways.com/shops/leavitt ... tive-works
Projects
-2.5" scale Class A 20 Ton Shay
Steam Siphon: https://www.shapeways.com/shops/leavitt ... tive-works
- gwerhart0800
- Posts: 225
- Joined: Wed Feb 27, 2008 11:02 pm
- Location: Loveland, CO USA
Re: Penberthy Injector question
I had a Penberthy BB-21 on a traction engine it was mounted about 18 inches higher than the spot that it entered the boiler. I loved that injector ... it worked every time without fail.
George Erhart
Loveland, CO
https://lovelandcreatorspace.com
Loveland, CO
https://lovelandcreatorspace.com
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- Posts: 2930
- Joined: Mon Nov 10, 2014 1:39 pm
- Location: Woodinville, Washington
Re: Penberthy Injector question
Decided to leave the starboard injector down low to the ground, pending some test runs this weekend. This new output line is a bit klugey. But it eliminates no less than seven previous 90* bends in the pressure output line leading to the boiler. I made up the new output line out of one length of 3/8” black iron pipe - heated red hot with a torch and bent to shape around a piece of 4” round stock.
Also going to fire up a Christmas train next week for the neighborhood. So erring on the side of not getting caught with a half completed remount in some new location.
Also connected the port injector. Likely this is the original factory position for injectors on both sides of the Loco. Needs a wash down and some brass polish - might happen during tomorrow’s test run...
Also going to fire up a Christmas train next week for the neighborhood. So erring on the side of not getting caught with a half completed remount in some new location.
Also connected the port injector. Likely this is the original factory position for injectors on both sides of the Loco. Needs a wash down and some brass polish - might happen during tomorrow’s test run...
Moderator - Grand Scale Forum
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
Re: Penberthy Injector question
Some flexibility in the injector delivery line is good. Full sized locos need that flex to accommodate expansion of lines.
Curves on those delivery lines are on purpose, not by accident.
Probably less important on our smaller locomotives.
~RN
Curves on those delivery lines are on purpose, not by accident.
Probably less important on our smaller locomotives.
~RN