The Steamboating Forum

What would cause this? I have run a Penberthy on my other boat. I know the sound it makes when it engages. This one is engaging. The water flowing from the overflow is is just a big stream, not high pressure. The fact that there is a good flow tells me the line to the backup tank is clear and the elevation is not too great (2 Feet). The supply is lake temperature. I have checked the discharge and it is clear into the boiler through a new one-way valve and an open gate valve.
Here is the big kicker. I swapped it with a new Pentherby I had exactly the same thing happened. The overflow port is wide open right at the Pentherby.
Help please, I need this backup method of boiler water elevation maintenance.

Wendell

Try cutting back on the water supply a little to see if it stops, it could just be overflow.

Minimum requirements for a working injector are a good water supply with no air entrained, good dry steam supply (within the injectors range), and somewhere for it to go, e.g. no shut valve between it and the boiler.

Hello Mike from middle earth. I have been to middle earth in New Zealand. Is that where you are? I never had a Penberthy overflow on my other boat but, it makes good sense that there is a reason for an over flow port. DUH! I will try it.
Thanks

I too have visited Middle Earth in N.Z. but I actually live quite close to the original Middle Earth. Hope you have found the problem with your injector. A good clean out never hurts either.

aaaahhh you are in joly ole Britain. Yes, i cleaned the Penberthy thoroughly. As i said, I am very familiar with the sound of the Penberthy firing up. I am going in a few hours and will try out the infeed reduction idea. I will inform you of the result.
Thanks and give my regards to Gandalf.

I have found the answer to the question. Why does water flow out of the overflow? I found this important piece of information on Smokstak.
The stream flowing through the injector must be a purely liquid one, that is, it must not contain any steam or air. If it does, the resulting stream will not have enough weight combined with its velocity to overcome boiler pressure and will consequently flow out at the overflow valve. (Check the tail pipe & coupling nut, along with all of the water connections, as air . . . even in small amounts will cause an injector to operate erratical.)

Mike Rometer wrote:.

Minimum requirements for a working injector are a good water supply with no air entrained, .........

Uhhu! This is because the injector causes a reduced pressure in the water feed, and any kind of a leak will draw air, as it is lighter than water. It follows the old adage that "a vacuum will be satisfied".

Glad you've found the problem.

Mike

Yep uuhuh You had said that and I missed the idea of sucking air. I just thought that the nice outflow was evidence of a "good" supply.
Thanks

Read the Mar/Apr 2015 issue of Steamboating Magazine to be mailed out next Monday. There's a reprint at the end from an old Penberthy operators manual on how to install and operate a Penberthy (and by extension many other makes of injector). "Cause you're a subscriber you can read it, do it, and have it operating in no time.