I am looking to repair a March boiler feed pump that is feeding an ottaway steam train in Northern California.
The steam side is 1.5” diameter and the water side is 7/8”. It’s apart at the moment so I do not have the stroke measurement.
I like the method in the Artisan steam engine piston rings using carbon filled PTFE but I am not finding material this offered at the common vendors in the 1” size. I have a mill and lathe of reasonable capacity.
It looks like this question about availability is posted every few years so this is my turn and I am interested in sources and alternatives.
The water side looks like cast iron with a very loose fit. The pump runs but it’s not filling the boiler so I would like to start with rings and then move through valves and plumbing.
Seal options for boiler feed pump?
- Bill Shields
- Posts: 10595
- Joined: Fri Dec 21, 2007 4:57 am
- Location: 39.367, -75.765
- Contact:
Re: Seal options for boiler feed pump?
Use square braided packing and cut rings to fit.
Or use graphite tape and wind it around to fill the gland.
Been working for 100+ years, no reason to reinvent the wheel.
Or use graphite tape and wind it around to fill the gland.
Been working for 100+ years, no reason to reinvent the wheel.
Too many things going on to bother listing them.
-
- Posts: 534
- Joined: Thu Mar 13, 2003 10:38 pm
- Location: Pickering Ontario Canada.
Re: Seal options for boiler feed pump?
For soft packing to have a long life the piston it is fitted on should fit the bore with no more than about 5 thous total clearance, preferably less.
Regards David Powell
Regards David Powell
-
- Posts: 2930
- Joined: Mon Nov 10, 2014 1:39 pm
- Location: Woodinville, Washington
Re: Seal options for boiler feed pump?
Can you post photos of the pump? The only feed pump on my Ottaway is a 1” cylinderical pump mounted behind the port cylinder, next to the smokebox saddle. Never knew of a different style pump…
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: Seal options for boiler feed pump?
It looks link I am able to post photos. I figured there would be post limits.
This ottaway lives in the Bay Area and this March pump was a gift from one of the steam clubs in place of the injector. It’s not original and it struggles. I am hoping new rings help.
I will measure the grove and try to find packing. This is the water side and the existing rings look like cast iron.
I would still like to build the ring for fun but cannot source graphite filled ptfe or substitute.
This ottaway lives in the Bay Area and this March pump was a gift from one of the steam clubs in place of the injector. It’s not original and it struggles. I am hoping new rings help.
I will measure the grove and try to find packing. This is the water side and the existing rings look like cast iron.
I would still like to build the ring for fun but cannot source graphite filled ptfe or substitute.
Last edited by Pwallace on Fri Dec 09, 2022 12:50 am, edited 1 time in total.
Re: Seal options for boiler feed pump?
My understanding is that the small inboard piston on the port side is part of the optional air brake system.Glenn Brooks wrote: ↑Thu Dec 08, 2022 12:35 am Can you post photos of the pump? The only feed pump on my Ottaway is a 1” cylinderical pump mounted behind the port cylinder, next to the smokebox saddle. Never knew of a different style pump…