Penberthy Injector question

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: cbrew, Harold_V

Post Reply
Glenn Brooks
Posts: 2930
Joined: Mon Nov 10, 2014 1:39 pm
Location: Woodinville, Washington

Penberthy Injector question

Post by Glenn Brooks »

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
Attachments
4BAE0858-A094-4A31-937F-67E8DCDC4E85.jpeg
27B5C7C5-87A9-468C-AA23-8F6E973064F5.jpeg
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....
User avatar
AnthonyDuarte
Posts: 491
Joined: Tue Jan 19, 2010 10:46 am
Location: Orange, CA
Contact:

Re: Penberthy Injector question

Post by AnthonyDuarte »

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
User avatar
DianneB
Posts: 733
Joined: Tue Aug 21, 2012 3:05 pm
Location: Manitoba, Canada

Re: Penberthy Injector question

Post by DianneB »

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.
User avatar
FLSTEAM
Posts: 1571
Joined: Sun Jan 05, 2003 10:55 am
Location: Central Florida

Re: Penberthy Injector question

Post by FLSTEAM »

No problem with a 2' lift. I have used 1/4 and 3/8 in.

John B.
Craig
Posts: 48
Joined: Fri Jan 10, 2003 5:29 pm
Location: Lemoore, CA

Re: Penberthy Injector question

Post by Craig »

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.
User avatar
Fred_V
Posts: 4370
Joined: Sun Jan 12, 2003 3:26 pm

Re: Penberthy Injector question

Post by Fred_V »

I think a Penberthy will lift about 12 feet. The output is not as fussy as miniature units either.
Fred V
Pensacola, Fl.
Soot n' Cinders
Posts: 983
Joined: Wed Jun 27, 2012 5:24 pm
Location: Marietta, Georgia

Re: Penberthy Injector question

Post by Soot n' Cinders »

Craig 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.
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 way
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

Steam Siphon: https://www.shapeways.com/shops/leavitt ... tive-works
User avatar
gwerhart0800
Posts: 225
Joined: Wed Feb 27, 2008 11:02 pm
Location: Loveland, CO USA

Re: Penberthy Injector question

Post by gwerhart0800 »

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
Glenn Brooks
Posts: 2930
Joined: Mon Nov 10, 2014 1:39 pm
Location: Woodinville, Washington

Re: Penberthy Injector question

Post by Glenn Brooks »

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.
0E8CA9A9-807F-48F0-B694-7FD82E55EE69.jpeg
280F6ACB-1390-4BEF-95C1-2B876F2EC282.jpeg
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.
DF039CA5-95B9-4DBC-AB99-ABEE2743F529.jpeg
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....
User avatar
NP317
Posts: 4557
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon, USA

Re: Penberthy Injector question

Post by NP317 »

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
Post Reply